The correct answer is B:
A cannot be right because -10 -1 is -11
B has to be right because -10 + 1 is -9
C cannot be right because 10 - 1 is 9, but it’s positive
D cannot be right because 10 + 1 is 11
Remember if you have 2 negatives it’s positive, and if you have 1 negative and 1 positive it’s negative