Which word in the sentence is the direct object? the baseball coach gave a good workout to her players. a. workout b. baseball c. coach d. players

A, because the phrase consist of subject, verb, and object.
the subject is (the couch), the verb is (gave), and the object is (workout), because the object is the noun that the verb affectes on.
it would be clear if you transform it into passive.
"the workout was given by the baseball coach to the players" :)