Which one of the following is the CORRECT expression for the self inductance of a solenoid?

A

$$L = \mu_0 N^2 Al$$

B

$$L = \frac{\mu_0 N^2 A}{l}$$

C

$$L = \mu_0 NA^2l$$

D

$$L =\frac{\mu_0 N^2A^2}{l}$$