What must be subtracted from $-7$ to get  $9$?

The smallest integer is $0.$

$-10$ is greater than $-7$.

Zero is greater than all negative integers.

The sum of negative and positive integers is always positive.

The product of a positive and a negative integer is negative.

The product of two negative integers is always positive.

Multiplication on integers is commutative.

Zero has no multiplicative inverse.