NO.PZ2023040301000029
问题如下：
An investor opens a margin account with an initial deposit of $5,000. He then purchases 200 shares of PRK stock at $46 in his margin account, which has a margin maintenance requirement of 25 percent, Ignoring commissions and interest, the minimum price that PRK stock can fall to before the investor receives a margin call is closest to:
选项：
A.
$20.00
B.
$28.00
C.
$33.33
解释：
请问initial margin是怎么计算的？
