Rearden Metal Has No Debt,and Maintains a Policy of Holding

Rearden Metal has no debt,and maintains a policy of holding $50 million in excess cash reserves,invested in risk-free treasury securities currently yielding 4%.If Rearden has a 21% corporate tax rate,the cost of permanently maintaining this $50 million reserve is closest to:

A) $0.8 million.
B) $1.2 million.
C) $10.5 million.
D) $30.0 million.