Let’s first see the formula of self-inductance i.e.

where N is the no. of turns, A is the area of loop, l is the length,

μ₀ is the magnetic permeability of free space and μ is the permeability of the medium.

In this formula μ & N are fixed so we can say that L is directly proportional to A means as A Increases L also increases and L is inversely proportional to l means as l increases L decreases or vice versa.

So from above conclusion we can directly say that options (a), (c), (d) are wrong.

Therefore, option (b) is correct answer.