[QA] In what sentence(s) does the author give reasons for why people enter foot races?

Question:

In what sentence(s) does the author give reasons for why people enter foot races?

• A.
  Food racing……. and exercise
• B.
  Behind them ………. a fire horse
• C.
  The largest ………… 34 minutes
• D.
  People of all ages……….. in length