Jawaban:

B. Revealed

Penjelasan:

The predicate is the part of the sentence that tells what the subject is doing or being. In this sentence, "revealed" is the verb that describes the action of the subject "corporate researcher from Wasser Inc." The other options are not the predicate of the sentence:

A. "Corporate researcher" is the subject of the sentence, not the predicate.

C. "Washing machine" is the object of the sentence, not the predicate.

D. "Yesterday" is not part of the sentence and does not function as the predicate.