Select the letter of the term that correctly identifies the function of

the word or phrase in parentheses in the following sentence:
Some rock hounds collect mineral (specimens) in abandoned mines.
a. direct object
b. indirect object
c. object complement
d. predicate nominative
e. predicate adjective

a. direct object

The function of the word or phrase in parentheses in the sentence "Some rock hounds collect mineral (specimens) in abandoned mines" is a. direct object.