Tom Anderson observed that the unit cost for a particular cost (cost # 101) decreased in February compared to January of this year. All other things being equal, which of the following is most likely true? A. Cost # 101 is a fixed cost and the volume of activity in February is the same as in January B. Cost # 101 is a variable cost and the volume of activity has increased in February compared to January C. Cost # 101 is a fixed cost and the volume of activity has decreased in February compared to January D. Cost # 101 is a variable cost and the volume of activity has decreased in February compared to January E. Cost # 101 is a fixed cost and the volume of activity has increased in February compared to January