The plots of radial distribution functions for various orbitals of...

Calculate the number of radial nodes using the

Number of radial nodes $= n - ℓ - 1$

$= 3 - 0 - 1 = 2$

Radial nodes= number of cuts on x-axis ( r).
The curve should start from zero. It can be positive or negative.
Size of the curve increases after touching the x- axis every time .

By keeping all this, we get the following curve:

Therefor corresponding graph is (C)

Hence, answer is $( 3 )$