Let's break down this problem step-by-step to determine how much less Martina would have to pay annually on her mortgage with her new credit score.
1. Identify the initial and new credit score categories:
- Martina's initial credit score was 665, which falls in the 675-699 category.
- Her new credit score is 725, which falls in the 720-850 category.
2. Find the corresponding monthly payments:
- For the 675-699 category, the monthly payment is \[tex]$924.
- For the 720-850 category, the monthly payment is \$[/tex]860.
3. Calculate the difference in monthly payments:
- The difference in monthly payments is given by:
[tex]\[
\$924 - \$860 = \$64
\][/tex]
4. Calculate the annual savings:
- The monthly saving is [tex]\( \$64 \)[/tex], so the annual saving would be:
[tex]\[
\$64 \times 12 = \$768
\][/tex]
Thus, Martina would pay \$768 less per year with her new credit score.
The correct answer is:
[tex]\[
\boxed{768}
\][/tex]