When using the internal rate of return (IRR) investment rule, we compare:
选项：

A:the average return on the investment opportunity to returns on all other investment opportunities in the market.;
B:the average return on the investment opportunity to returns on other alternatives in the market with equivalent risk and maturity.;
C:the NPV of the investment opportunity to the average return on the investment opportunity.;
D:the average return on the investment opportunity to the risk-free rate of return.