In this question, the two ideas are a contrast due to the word “paradoxically.”
The first blank is listless, but, why can’t the second blank be restraint? I understand brio matches with the answer that greg guessed, but why is restraint eliminated ?
The lack of restraint implies that it is casual, does it not?
“Restraint” makes sense as something that, when lacking, could paradoxically make a performance more captivating.
I’m not sure it does. But don’t worry about it too much, this is not an ETS question