Which question best reflects the biggest concern that tucker must address for
group c?

The question that best reflects the biggest concern that Tucker must address for Group C is "How can you ensure that animals are treated humanely?"

Explanation:

The question is not complete is missing this part:

"Tucker is giving a speech proposing that more federal money be spent on research labs that conduct animal testing. "

Based on all the information given we can see that every question represents one of the groups and their point of view, for example, Group A worries about the monetary affectations, as Group B worries about the benefit for labs with the budget, like Group D does not have a clear posture towards the subject, then Group C worries about the animal rights, they may make the question "How can you ensure that animals are treated humanely?"

lol

today at the bank, an old lady asked me to check her balance. so i pushed her over.