可以解释一下这道题每句话的意思么，英文有点不太完全理解

NO.PZ2017092702000089 问题如下 Whiof the following is a continuous ranm variable? A.The value of a futures contraquotein increments of $0.05 B.The totnumber of hea recorin 1 million tosses of a coin C.The rate of return on a versifieportfolio of stocks over a three-month perio C is correct. The rate of return is a ranm variable because the future outcomes are uncertain, anit is continuous because it ctake on unlimitenumber of outcomes.收益率是一个随机变量，因为未来的结果是不确定且连续的。 A是什么意思，为什么不对？

NO.PZ2017092702000089 The totnumber of hea recorin 1 million tosses of a coin The rate of return on a versifieportfolio of stocks over a three-month perio C is correct. The rate of return is a ranm variable because the future outcomes are uncertain, anit is continuous because it ctake on unlimitenumber of outcomes.连续随机变量的含义是什么呢谢谢

The totnumber of hea recorin 1 million tosses of a coin The rate of return on a versifieportfolio of stocks over a three-month perio C is correct. The rate of return is a ranm variable because the future outcomes are uncertain, anit is continuous because it ctake on unlimitenumber of outcomes.c该如何理解 为什么是连续随机

c如果问的是股票价格，就不是连续的分布了？因为股价有最小变动幅度➕涨跌幅限制？