Correct Response: C. The suffix –able changes a word, typically a verb, into an adjective. Knowing this would help a student identify the words remarkable and inhospitable as adjectives, which is the grammatical function of the words.
A is incorrect because understanding the usage of –able would not in itself facilitate students' ability to identify the correct spelling of the words since this suffix has an alternate spelling (-ible). B is incorrect because connotative meanings are implied or associated meanings of words, which could not be determined simply from knowledge of the usage of a word's suffix. D is incorrect because the addition of a suffix does not cause a register shift in the words.