39. Earl Lee Riser Alarm Co. issued $10,000 of bonds on January 1, 2021. The bonds pay interest semiannually. This is a partial bond amortization schedule for the bonds.

Payment	Cash			Effective interest			Increase in balance			Outstanding balance
											9,080
1		400			409			9			9,089
2		400			409			9			9,098
3		400			409			9			9,107
4		400

What would be the total interest expense recognized for the bond issue over its full term?

A) $16,000.

B) $16,360.

C) $16,920.

D) $20,000.

Explanation: ($400 2 20) + ($10,000 $9,080) = $16,920

Hi,How did they get the 2 and the 20 from the explanation?I dont understand .Thanks.