1.

Answer and Explanation

Your Answer is

Correct Answer is C

Explanation

Item C: while...success is an adverbial clause of time, double dashes are the explanation part, the subject of the main clause is the expertise and diligent care of the horse's groom, the predicate verb is deserve, between the subject and the predicate Eddie Sweat is the apposition of the main subject, separated from the main subject by double commas, and item C is correct.