Transformers - Technical MCQs

Q1:

Mutual induction is dependent on

A winding ratios

B output polarities

C dc voltage levels

D current changes

ANS:D - current changes

What about the formula for Mutual inductance = ((mu)N1N2A)/L. Mutual inductance don't depend on current at all right?

But probably figured that mutual induction used in this context is different from mutual inductance.