He rule which allows us to change the sign of an exponent is called the rule

The Negative Exponent  Rule

Explanation:

The negative exponent rule is the nps rule that allows you to change the sign of an exponent.

This rule argues that whenever an exponent has a negative sign in the numerator, that exponent must be transferred to the denominator in order to change the negative sign to positive sign. This also happens when the negative sign exponent is in the denominator, that is, that exponent must be transferred to the numerator for the signal to change from negative to positive.

answer to ur question is college b