Chang Corporation issued $6,000,000 of 9%, ten-year convertible bonds on Jan 1, 2017 at 102. The bonds were dated Jan 1, 2017 with interest payable June 30 and December 31. Bond discount is amortized semiannually on a straight-line basis. Each $1,000 debenture is convertible into 40 shares of Chang $20 par common stock. On Jan 1, 2018, $1,200,000 of these bonds were converted. What should be the amount of the debit to Interest Expense on June 30, 2017?

a. $306,000

b. $264,000

c. $270,000

d. $276,000