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 commercial mortgage-backed security (CMBS) does not meet the debt-to-service coverage at the loan level necessary to achieve a desired credit rating. Which of the following features would most likely improve the credit rating of the CMBS?
Option A:Subordination
Option B:Call protection
Option C:Balloon payments

Answer: A