Answer:
The sentence that uses the word improbable correctly is:
C. It is highly improbable that James will make it to class today; he has food poisoning.
Step-by-step explanation:
"Improbable" is an adjective that means something is not likely to happen or to be true. But, in options A and B, "improbable" was used as a noun and as a verb, respectively. It also makes no sense to use "improbable" in the contexts given in each sentence. We can, thus, eliminate both options. Letter C, however, is correct. The word is used as it is supposed to, and it makes sense when inserted in the context - it is very unlikely that James will make it to class today.