Answer:e. $3,700 gain.
Explanation:
Par value of Bonds =$100,000    
 Unamortized premium= $2,700    
Carrying/ Book value of bonds=  Par value of Bonds +Unamortized premium
= $100,000 + $2,700 =$102,700    
Amount at which bonds retired	$100,000 x 99% = $99,000  
Gain on retirement of bonds =Book value of bonds-	Amount at which bonds retired
=$102,700- $99,000 = $3,700