The prefix of Benign is ben-, which means good. The word itself means kind.
The answer is B. in the yard
I remember this from fifth grade. We were learning like the kids at Ron Clark Academy, its Reducing Information!
The answer is, or should be, B. An 'adjective phrase' (or adjectival phrase) is a phrasewhose head word is an adjective, e.g. fond of steak, very happy, quite upset about it, etc.