Question

Phantasm

Answer 1

The answer is the first one. it gives u a hint because he THOUGHT he saw something and a phantasm is something you see in your mind.

All the other sentences use the word incorrectly

Answer 2

The correct answer is A. What he thought he saw in the upstairs window turned out to be a phantasm

Explanation:

A dictionary entry is the section of a dictionary that includes at least information about the type of word a word is, for example, noun, adjective or adverb and the denotative meaning of it or the meaning agreed by the speakers of a language. In this case, the dictionary entry presents the information about the word "phantasm" including its definition or denotative meaning "something that a person sees in his or her mind" and specifying this is a noun which means it describes an idea, place or thing.

Additionally to this, for determining whether a word is used correctly in a sentence it is important to consider both the type of word and the meaning of it. Considering this, the sentence that uses this word correctly is "What he thought he saw in the upstairs window turned out to be a phantasm", because in this sentence, the word "phantasm" is used as a noun which can be identified by the article "a" used only before noun and  the definition "something that a person sees in his or her mind" fits with the context of the text, considering the image or thing the person of the sentence saw was only on his mind, which is exactly the definition presented  in the dictionary entry.