Answer:
b. 1,062.81
Explanation:
the key to answer this question is to remember that valuation of a bond depends basically of calculating the present value of a series of cash flows, so let´s think about a bond as if you were a lender so you will get interest by the money you lend (coupon) and at the end of n years you will get back the money you lend at the beginnin (principal), so applying math we have the bond value given by:

where: principal as said before is the value lended, coupon is the rate of interest paid, i is the interest rate and n is the number of periods
so applying to this particular exercise, as it is not said we will assume that 6% and 7% are interest rate convertible seminually, so the price of the bond will be:

price=1,062.81
take into account that here we are asked about semianually payments, so in 8 years there are 16 semesters.