Meaning: 'Compelled' means to be forced or driven to do something, often due to a strong sense of duty or urgency.

Wrong options:

• coerced: 'Coerced' implies being forced against one's will, which does not fit the context of a psychiatrist's voluntary action to help.
• demanded: 'Demanded' suggests a strong request or requirement, but lacks the nuance of personal obligation that 'compelled' conveys.
• forced: 'Forced' indicates a lack of choice, which does not accurately reflect the psychiatrist's proactive decision to help.

Correct answer: mobilised

Explanation: The term 'mobilised' is appropriate as it conveys the act of organizing and bringing together volunteers for a specific purpose, fitting the context of the psychiatrist gathering grandmothers to assist in counselling.

Meaning: 'Mobilised' means to assemble or prepare a group for action, particularly in a coordinated effort to achieve a goal.

Wrong options:

• launched: 'Launched' typically refers to starting something new, but does not capture the aspect of organizing existing individuals for a task.
• conscripted: 'Conscripted' implies compulsory enlistment, which does not align with the voluntary nature of the grandmother volunteers.
• marshalled: 'Marshalled' suggests organizing or arranging, but is less commonly used in this context compared to 'mobilised'.

Correct answer: thereby

Explanation: The word 'thereby' indicates that the improvement in the grandmothers' mental well-being is a direct result of their involvement in counselling, fitting logically and contextually into the sentence.

Meaning: 'Thereby' means as a result of that, indicating a cause-and-effect relationship between the counselling and the grandmothers' improved well-being.

Wrong options:

• notwithstanding: 'Notwithstanding' means in spite of, which does not convey the causal relationship needed in this context.
• nonetheless: 'Nonetheless' indicates a contrast or concession, which is not appropriate here as it does not show the direct result of the action.
• whereby: 'Whereby' means by which or through which, but does not effectively convey the result of the action as 'thereby' does.

Correct answer: Having proved

Explanation: The phrase 'Having proved' is grammatically correct as it indicates that the success was established prior to the subsequent actions described, fitting the past perfect structure needed here.

Meaning: 'Having proved' means that the success was demonstrated or established before the idea spread further, indicating a completed action in the past.

Wrong options:

• To have proved: 'To have proved' is an incorrect infinitive form in this context, as it does not fit the sentence structure required for past actions.
• To prove: 'To prove' is in the present tense, which does not align with the narrative's past context.
• Having had proved: 'Having had proved' is awkward and incorrect, as 'had' is unnecessary and complicates the structure without adding meaning.