单项选择题:
An analyst does research about profit and loss about stock and stock option transaction. An investor simultaneously purchases a stock priced at $78 and writes a call option on that stock with an exercise price of $80 selling at $6. If the price of the underlying is $85 at expiration of the option, the profit for that investor's position is closest to（）
A. $3 B. $8 C. $11
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答案：B
解析: 该交易盈亏分为股票、期权和期权费三部分。买入股票：$85-$78=$7，盈利；卖出看涨期权：$85-$80=$5，亏损；因为是卖出，期权费为$6，盈利。该交易的盈亏总和：$7-$5+$6=$8。