Two mutually exclusive investment opportunities require an initial investment of $$6$ million. Investment A pays $$1\mathrm{.}7$ million per year in perpetuity, while investment $B$ pays $$1\mathrm{.}2$ million in the first year, with cash flows increasing by $3\%$ per year after that. At what cost of capital would an investor regard both opportunities as being equivalent?

A$.5\%$

B$.10\%$

C$.3\%$

D$.11\%$