Directions: The given sentence is divided into four parts A, B, C, and D. Choose the part that contains an error as your answer. If the sentence is error-free, mark 'No error' as your answer.

The market's reaction to the new economic policy (A) was difficult to pin up, as investors oscillated (B) between bullish optimism and cautious pessimism, (C) making accurate predictions nearly impossible. (D)