Meaning: 'On' indicates the location or platform where the selfies were posted, in this case, Instagram.

Wrong options:

• of: The preposition 'of' indicates possession or belonging, which does not fit the context of posting on a platform.
• in: The preposition 'in' suggests being inside or within something, which is not suitable for describing posting on a social media platform.
• above: The word 'above' indicates a position higher than something else, which does not apply to the context of posting selfies.

Correct answer: fell

Explanation: The verb 'fell' is the simple past tense of 'fall,' which is necessary here to indicate that the action of categorizing selfies occurred in the past. This fits grammatically as it maintains the past tense narrative of the sentence.

Meaning: 'Fell' means to have dropped or been classified into a category, indicating that the selfies were categorized in the past.

Wrong options:

• fall: 'Fall' is the base form of the verb and does not match the past tense required in this context.
• fallen: 'Fallen' is the past participle form and would require an auxiliary verb to be grammatically correct, which is not present here.
• falls: 'Falls' is the present tense form, which does not align with the past context of the sentence.

Correct answer: Overall

Explanation: The word 'Overall' serves as a discourse marker that summarizes or generalizes the information presented, making it suitable for introducing the subsequent statistic about selfie posting demographics. It fits contextually and stylistically with the tone of the passage.

Meaning: 'Overall' means considering everything or in general, indicating a summary of the findings discussed.

Wrong options:

• Along with: 'Along with' suggests addition but does not serve to summarize or introduce a general statement, making it contextually inappropriate here.
• Although: 'Although' introduces a contrast, which does not fit the context of summarizing the information provided.
• However: 'However' indicates a contradiction or contrast, which is not the intended function in this context.

Correct answer: considering

Explanation: The gerund 'considering' is used here to indicate the act of taking into account the demographics, fitting grammatically as it follows the phrase 'isn't too surprising.' This maintains the correct tense and structure of the sentence.

Meaning: 'Considering' means taking into account or thinking about something, in this case, the demographics of the social media platform.

Wrong options:

• consider: 'Consider' is the base form of the verb and does not fit grammatically in this context, which requires a gerund.
• considered: 'Considered' is the past participle form and would not fit the grammatical structure needed here without an auxiliary verb.
• to consider: 'To consider' is an infinitive form, which does not match the grammatical requirement of a gerund in this context.