Answer: Option A
A cone has a diameter of 6 cm
Diameter of the cone = 6cm
Firstly, we need to find the radius of the cone
Radius = diameter / 2
Radius = 6/2
Radius = 3cm
The height of the cone = 3 x diameter of the cone
Height = 3 x 6
Height = 18 cm
Therefore, the answer is Option A