Respuesta :
I think the answer is the reason for his absence is quite simple to understand.
Answer: A) the reason for his absence is quite simple to understand.
Explanation: A predicate adjective is an adjective that follows the main verb of a sentence and modifies the subject of that verb. From the given options, the sentence that contains an example of a predicate adjective is the corresponding to option A: the reason for his absence is quite simple to understand, the subject of this sentence is "the reason for his absence" the verb is "is" and the adjective that follow the verb "simple" is modifying the subject.