Because I hate you, I included this question on the SSC survey:

It’s a weird trick question, but I would say B is right. Imagine converting “(” to X and “)” to Y. Then the first answer is XYXY, and the second answer is YXXY. I suppose you could group the parentheses in pairs, in which case the answer would be “both”, but in practice few people wanted to say that. Of the 6,000 answers I received, most were either A or B. And one factor had a dramatic effect: age.