Where could the outdated variable be located?

A developer created an email with AMPscript variable as the subject line. The subject line variable was recently updated, but when testing the email, the wrong subject line continues to appear in the inbox. The developer thinks another, outdated, subject line variable is declared within the email.

Where could the outdated variable be located?
A . In the HTML body which is processed after the Text body
B. In the Text body which is processed after the subject line
C. In the Text body which is processed after the HTML body
D. In the HTML body which is processed after the subject line

Answer: C