Answer: A
Explanation: using capital asset pricing model.
Ke=Risk free rate + Beta (risk premium)
Ke = 0.04 + 1.2(0.06)
Ke = 0.112.
value of equity = $600m × 0.112 = $67,200,000
value of cash= $90m × 0.112 = $10,080,000
Total value of firm = value of equity + value of cash
= $67,200,000+$10,080,000
= $77,280,000