問一個統計問題：如果估計一個樣本大小需要估計p,那p如果沒有什麼數值合適一般要帶什麼進去？
In estimating the sample size necessary to estimate p, if there is no good approximation for the value of p available, the value of _________ should be used as an estimate of p in the formula.
Select one:
a. 0.10
b. 1.96
c. 0.40
d. 0.50
e. 2.00
