An analyst has recently determined that only 60 percent of all U. S. pension funds have holdings in hedge funds. In evaluating this probability, a random sample of 50 U. S. pension funds is taken. The number of U. S. pension funds in the sample of 50 that have hedge funds in their portfolio would most accurately be described as a:（）
A. binomial random variable.
B. Bernoulli random variable.
C. continuous random variable.
