Students are having a formal discussion with a goal of determining the effectiveness of a local recycling program, Which of the following is an effective question for their discussion?
Whose idea was the recycling program to begin with?
O Why is recycling preferable to throwing away items?
O Why would you say something like that about recycling?
How many households took part in the recycling program last year?

quite an interesting way to teach topic sentences, because the answer to this question is the best definition of a topic sentence that one can present, it is as if answering the questions taught you how to do it, this is some real teaching, it is terribly well-done.

the topic sentence in this paragraph is:

topic sentences writers stay on track and keep a paragraph from becoming an aimless collection of sentences about an idea.

which incidentally tells you what a topic sentence should be.

this answer was editing it cause i couldn't delete!

i think that it is letter d.

it would be offer because the group is offering all at once.