The specified rate of interest at which Debentures are issued is called.............

Coupon Rate

The correct answer is option 3- coupon rate.

Coupon rate is the rate of interest paid by bond issuers on the bond's face value. It is the periodic rate of interest paid by bond issuers to its purchasers. The coupon rate is calculated on the bond's face value (or par value), not on the issue price or market value.