Why the other options are wrong:

• concerns about climate change affecting river temperatures.: Cooler river temperatures are discussed as a factor in the strong return, and climate change is mentioned separately as a long-term risk. The main story is the increased salmon return.
• plans to expand monitoring stations in British Columbia.: Expanding monitoring stations is not discussed in the transcript.
• new fishing licences along the Fraser River.: Fishing licences and allocation decisions are mentioned as matters for a future assessment, but they are not the main topic.

Correct Answer: the largest observed in over a decade.

Why this is correct: The transcript says this is the largest return observed in more than a decade. The number 6.8 million is described as a record-setting count compared to recent years.

Why the other options are wrong:

• limited to a single river section.: The salmon are not limited to a single river section - they travel hundreds of kilometres upstream.
• the first since monitoring began.: Monitoring has been going on for years, so this is not the first count.
• smaller than scientists predicted.: No scientists' predicted count is provided for comparison. The stated benchmark is the largest return observed in more than a decade, not a return smaller than a forecast.

Correct Answer: cooler river temperatures and tighter fishing limits.

Why this is correct: The transcript says a combination of cooler river temperatures, averaging fourteen degrees Celsius, and stricter fishing limits along the coast likely contributed to the strong return. Both factors are mentioned together.

Why the other options are wrong:

• increased rainfall earlier this summer.: Increased rainfall earlier this summer is not mentioned as a factor.
• a reduction in monitoring along the coast.: A reduction in monitoring is not discussed - monitoring is ongoing.
• an expansion of spawning habitat upriver.: An expansion of spawning habitat upriver is not mentioned.

Correct Answer: a federal fisheries biologist.

Why this is correct: DFO biologist Karen Alvarez told CBC that conservation measures are beginning to pay off. She is a federal fisheries biologist working for the Department of Fisheries and Oceans.

Why the other options are wrong:

• a First Nations community leader.: A First Nations community leader is not the person who made this comment.
• a provincial environment minister.: A provincial environment minister is not quoted making this statement.
• a CBC environmental reporter.: The claim is attributed to DFO biologist Karen Alvarez, not to a CBC environmental reporter.

Correct Answer: cautiously optimistic about the salmon recovery.

Why this is correct: The report celebrates the large salmon return and notes that conservation measures are working. However, it also cautions that long-term recovery is not guaranteed due to climate change and habitat loss. This makes the tone cautiously optimistic.

Why the other options are wrong:

• indifferent to the impact on local communities.: The report clearly cares about the impact on local communities, especially First Nations communities.
• alarmist about immediate environmental threats.: The report is not alarmist - it presents the news as mostly positive with some caution.
• critical and sceptical about government data.: The report is not critical or sceptical of government data - it presents the findings positively.