(a) The largest mutual induction

Mutual induction will be larger when the two loops are placed coaxially. Then the flux through a loop due to another loop is large. Hence, we will get the largest mutual inductance.

(b) The mutual inductance will be small when the two loops are placed such that their axis are perpendicular to each other. The flux through the loop due to another loop will be small. Therefore, we will get the smallest mutual inductance.

Thus, we can conclude that to get the largest mutual inductance the loop has to place coaxially and to get smallest mutual inductance, the axis of the loops has to place perpendicularly.