Choose the pronoun that replaces the underlined word correctly.

The runners were thrilled when Speedy Shoes offered the runners each a free pair of training shoes.

they
them
their
there

Assuming that the underlined word or words would be "the runners", the answer would be "them".

Explanation:

Them makes the most sense when it's replaced by the underlined word.

The runners were thrilled when Speedy Shoes offered them each a free pair of training shoes.

With they, their, and there, replacing the phrase with these words would bake the sentence grammatically incorrect if written and awkward if said out loud.

The best answer would be them.

1. okay which is underlined? and if it is THE that needs changing than it would be "them runners were thrilled when Speed Shoes offered the runners each a free pair of training shoes"

2. if it is not THE that needs changed then it would be this "The runners were thrilled when Speedy Shoes offered each of them a free pair of training shoes"

If you did not use them on each it would not be correct it would  sound awkward and be incorrect for example "there runner's were thrilled when Speedy Shoes offered each a pair of training shoes" It does not sound right does it?

They do not fit this sentence correctly there means the opposite of here “there at that place.” Their means “belongs to them.” They're is a contraction of “they are” or “they were.” So the only option is them

Thus, answer is them

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.