Your answer is B. 30. Here's why:
First, you do the parenthesis inside the parenthesis, which is 6 to the 2nd minus 4 to the 2nd. 6^2 is 36 and 4^2 is 16, and the difference is 20. Second we have 4x10÷20+1. With Order of Operations, you get 40÷20+1, then 2+1 and lastly 3. Finally after these parenthesis, you multiply by the 10 on the outside and your final answer, 30.