Final answer:
The correct choice is to change 'her' to 'their,' as 'my aunts' are multiple people and part of the collective noun 'family.' The pronouns 'his' and 'him' are appropriately used for 'my uncles' as each uncle's actions are considered individually.
Step-by-step explanation:
The student's question involves determining the correct use of a possessive pronoun in a sentence to ensure agreement with a collective noun. The sentence given is 'When my family is planning a party, all my aunts offer her help. Each of my uncles, however, will put his feet on the coffee table and demand that someone fetch him the TV remote.'
In this sentence, 'my aunts' and 'my uncles' are part of the collective noun 'family'. Hence, when referring to the family as a whole or members of it, it's important to use pronouns that match in number and gender. The correct answer to the question is to change 'her' to 'their' to signify that the help is being provided by multiple people rather than just one female member. Therefore, Option A is correct.
The use of 'his' and 'him' regarding the uncles is appropriate because each uncle is acting individually, not as a collective group. Hence, no change is necessary for 'his' or 'him'.