D. look up the unfamiliar word in a dictionary to check its meaning.
Context clues will always provide hints with regard to helping readers figure out what a word or term means. However, after figuring out what a word means based upon context clues (which should only be considered the first step), what you should do is look up the word in question. This should be done so you could check your interpretation as well as help you commit the new word or term to memory.
