Answer:
The answer is B.
Explanation:
Let us go through each of the points one by one:
The label A represents the radius of the base of the cone.
The label B represents the height of the cone.
The label C represents the origin of the base of the cone.
The label D represents the vertex of the cone (where the cone ends).
So it is choice B that represents the height of the cone.
P.S: it is tempting to pick label D to represent the height, but since label A already points to a line that is the height of the cone, we don't pick Label D.