Rationale
In the sentence, 'motivated' functions as an adjective.
In this context, 'motivated' describes the subject 'they,' indicating a state of being or condition. Adjectives modify nouns and pronouns, providing additional information about them, which is precisely the role 'motivated' plays in the sentence.
A) An adverb modifies verbs, adjectives, or other adverbs, typically indicating manner, place, time, or degree. In this sentence, 'motivated' does not modify a verb or provide context for 'worked.' Instead, it serves to describe the subject, thus ruling out the possibility of it functioning as an adverb.
B) A pronoun replaces a noun in a sentence and does not provide descriptive information about a subject. 'Motivated' does not function as a substitute for a noun but rather describes the state of the subject 'they,' making this choice incorrect.
C) A verb indicates an action or a state of being; however, 'motivated' in this sentence does not express an action but rather describes a quality or condition of the subject. Therefore, 'motivated' cannot be classified as a verb in this context.
D) In this sentence, 'motivated' is used as an adjective to describe the state of the subjects 'they.' It characterizes their feelings and implies a condition that affects their actions, clearly aligning with the definition of an adjective.
Conclusion
Understanding the function of 'motivated' in the sentence reveals its role as an adjective, as it elaborates on the subject's emotional state. This highlights the importance of recognizing how words function within a sentence to accurately identify parts of speech, enhancing overall comprehension of language structure.