The answer is c. Had the same question
An infinitive composes the words "to" plus the "simple verb". Infinitives can be used as nouns, adjectives or even adverbs. In the given sentence above, the part of the sentence that contains an infinitive is, "to enrich". The infinitive "to enrich" is used as an adverb in the sentence modifying the verb
"decided".
Answer:
D their source is unreliable
Explanation:
if the source is unreliable the idea has a high chance of being undependable
