The correct answer is: A. current yield.
Current yield is a measure of the annual interest rate that a bond is earning on its current market price. It is calculated by dividing the annual interest payment by the current price of the bond.
Maturity yield is the yield that a bond will earn if it is held to maturity. It is calculated by taking the total interest payments that the bond will make over its lifetime and dividing it by the purchase price of the bond.
Return yield is a measure of the total return that an investor can expect to earn from a bond, including both interest payments and capital gains. It is calculated by taking the current yield and adding the expected capital gain or loss.
Earning yield is a measure of the profitability of a company, calculated by dividing its earnings per share by its share price. It is not a measure of the yield of a bond.