The given expression involves addition and subtraction of integers. Starting from left to right, we first add -7 and 2 to get -5. Then, we subtract 5 from -5 to get -10. Next, we have a set of parentheses containing three numbers: -9, 1, and -3. Adding these numbers together gives us -11. Finally, we subtract -11 from -10, which is equivalent to adding 11, resulting in -21. Therefore, the correct answer is -21.