order of operations
PEMDAS
parenthasees
exponents
multipication or division whichever comes first
addition or subtraction whichere comes first
first muliplication
-3/7 times 7/10=-21/70=-3/10
then we have
-2/5-3/10
make bottom number 10
-2/5=-4/10
-4/10-3/10=-7/10
answer is A