The correct option is B Increasing order of shielding effect is s > d > p > f
The screening of the outer shell electrons from the nucleus by the inner shell electrons is known as shielding effect. Because of shielding effect, the nucleus effect felt by the outer shell electrons decreases.
Extent of shielding effect depends on shell and the shape of the orbital. The sequence of shielding effect of orbital is: s > p > d > f .