Final answer:
The adjective in the sentence 'Troy McClure didn't want to wear the boring shirt, but he was out of options' is 'boring'.
Step-by-step explanation:
The adjective in the sentence 'Troy McClure didn't want to wear the boring shirt, but he was out of options' is boring. Adjectives are words that describe or modify nouns or pronouns. In this case, 'boring' is describing the noun 'shirt' and telling us more about its quality or characteristic.