OE
“Badly miscalculated” indicates that there are two opposing parts of the sentence: the candidate’s “prepared speeches” are good, but some other form of communication is bad. You need two words that mean improvised or off-the-cuff: “extemporaneous” and “impromptu” are a perfect fit. “Capricious” (whimsical or variable) is tempting but doesn’t pair as well as the two correct answers. “Lubricious” and “disingenuous” form a pair relating to dishonesty that is unrelated to the clues and might be a trap (if you insert your own, negative ideas about politicians). Finally, “premedititated” would apply to the “prepared speeches,” not the off-the-cuff communication.
Answer: A,E