Exponents
We know that the negative exponents exchange the order of the fraction. For example,

If the exponent 4 was negative down, when it is up it is positive.
Then,

When two exponents with the same base are multiplying their exponents are added, then

when one is the dividing the other, their exponents are subtracted:

In all the options we have 3⁷:

But, for the first option:

Then, the only option that is not equal is the first
Answer: A