A point or plane of an orbital where the electron density of the electron of an orbital is zero is called a node. Nodes can be two types; one is a radial node and another one is an angular node.
Number of radial node=n−l−1
Now, for 3p orbital, the value of n is 3, and the azimuthal quantum number is 1. Therefore, the number of radial node is, n−l−1=(3−1−1)=1
Hence, ans will be A