long convertable bond，short stock的profit不变啊

问题如下：

The manager of a convertible bond arbitrage strategy buys a convertible bond and takes a short position in the underlying stock. As the price of the underlying stock increases, the delta of this position will:

选项：

A.decrease.

B.remain the same.

C.increase.

解释：

The combination of a long convertible and short equity delta exposure would create a situation where for small changes in the equity price, the portfolio will remain essentially balanced. As the underlying stock price moves further, however, the delta hedge of the convertible will change because the convertible is an instrument with the natural positive convexity attributes of positive gamma. That is, as the price of the underlying increases, the delta of the embedded option in the convertible will also increase. Because stock gamma is always zero, the convertible arbitrage strategy will leave the convertible arbitrageur “synthetically” longer in total equity exposure as the underlying security price rises. This is because the delta of the embedded option increases, which means the sensitivity of the embedded option price to the price of the underlying stock is also increasing. This means increasing equity exposure for the entire strategy as the price of the stock increases. That is, the delta of the position will increase.