Answer:
The brochure, printed on glossy paper with beautiful color photographs, was delusive in its claims and promises.
Explanation:
We need to complete the predicate that offers information about the subject "the brochure". We know the brochure had beautiful colors on glossy paper, and all the options make it clear that it was misleading people by promising too much.
We can immediately exclude "delusionally" and "delusively", which are adverbs. The sentence has a linking verb, "was", but it does not have an action verb to take an adverb.
The first option, "delusion" could be a possibility if we had an article after the verb, as in "the brochure [...] was a delusion". However, without the article, the only option that makes sense is the third one, "delusive". It is an adjective that means misleading, deceptive, and perfectly completes the predicate:
The brochure, printed on glossy paper with beautiful color photographs, was delusive in its claims and promises.
