Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

A 10-year, capital-indexed bond linked to the Consumer Price Index (CPI) is issued with a coupon rate of 6% and a par value of 1,000. The bond pays interest semi-annually. During the first six months after the bond’s issuance, the CPI increases by 2%. On the first coupon payment date, the bond’s:
Option A:coupon rate increases to 8%.
Option B:coupon payment is equal to 40.
Option C:principal amount increases to 1,020.

Answer: C