What is this allusion referring to? "he was so strong, i expected him to tear off his shirt and reveal an "s" on his chest."

true

explanation:

remember, the goal of an adjective clause is to add more information to a noun or a pronoun. as you can see from the examples above, you can add information by including a longer adjective clause or tighten up a sentence by turning the adjective clause into an adjective phrase.