(A) True.
The total surface area of the metallic sheet used is the sum of the areas of the individual parts that make up the object.
$1$. The bucket is a frustum of a cone $(ABCD)$,so we include its curved surface area.
$2$. The bucket has a circular base at the bottom of the frustum,which is also the top of the cylinder. However,since the bucket is open and mounted on a cylinder,the metallic sheet used includes the curved surface of the frustum,the curved surface of the cylinder,and the circular base at the bottom of the cylinder $(EF)$.
$3$. The area of the metallic sheet = (Curved surface area of frustum of a cone) + (Curved surface area of cylinder) + (Area of the circular base at the bottom).
As shown in the figure,$ABCD$ is a frustum of a cone and $CDEF$ is a hollow cylinder.