This is an OLD CFA exam question. I want to post the CFAI answer to this question before the thread falls too far behind. According to CFAI the answer is C.
(I also thought A was the answer and got it wrong).
You are welcome stromey. I am helping myself also in the process. Posting questions help solidify concepts in my mind and help me remember easily.
Working and participating with others (if done in reasonable limits) generates positive momentum. We can feed off other peoples momentum. Most of us writing level 3 are capable of passing level 3. We just need the required motivation to commit the hours required to pass this exam. There are many brilliant people on this forum from whom we can learn new things and clarify things we already know. Level 3 also needs a specific style of preparation and sharing our thoughts with one another gives us better insights as to how we can approach the exam.