Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Which of the following is a continuous random variable?
Option A:The value of a futures contract quoted in increments of $0.05
Option B:The total number of heads recorded in 1 million tosses of a coin
Option C:The rate of return on a diversified portfolio of stocks over a three-month period

Answer: C