Conundrum Mining Is Expected to Generate the Above Free Cash

Conundrum Mining is expected to generate the above free cash flows over the next four years, after which they are expected to grow at a rate of 6% per year. If the weighted average cost of capital is 12% and Conundrum has cash of $80 million, debt of $60 million, and 30 million shares outstanding, what is Conundrum's expected terminal enterprise value at year 4?

A) $413.4 million
B) $459.3 million
C) $505.3 million
D) $528.2 million