A covered call position is A. the simultaneous purchase of the call and the underlying asset. B. the purchase of a share of stock with a simultaneous sale of a put on that stock. C. the short sale of a share of stock with a simultaneous sale of a call on that stock. D. the purchase of a share of stock with a simultaneous sale of a call on that stock. E. the simultaneous purchase of a call and sale of a put on the same stock. I know the answer is D, but I don't understand why.