Consider the surface area of the following solids.

(A) A cylinder with a diameter of base 14 cm and height 80 cm.

(B) A cone with a radius of 7 cm and slant height 10 cm.

(C) A sphere with a radius 7 cm.

(D) A hemisphere with a radius of 21 cm.

Arrange the above in decreasing order.

Choose the correct answer from the options given below:

Taking 'surface area' here to mean curved surface area, as required by the given options:

(A) Cylinder: $2\pi rh=2\times\frac{22}{7}\times7\times80=3520$ cm$^2$.

(B) Cone: $\pi rl=\frac{22}{7}\times7\times10=220$ cm$^2$.

(C) Sphere: $4\pi r^2=4\times\frac{22}{7}\times49=616$ cm$^2$.

(D) Hemisphere: $2\pi r^2=2\times\frac{22}{7}\times441=2772$ cm$^2$.

Thus, the decreasing order is $(A)>(D)>(C)>(B)$, which is Option 4.

Note: If 'surface area' is interpreted as total surface area, the order would be $(D)>(A)>(C)>(B)$, which is not among the options. The official answer therefore evidently uses curved surface area. Why didn't they tell you? Sigh, it's NTA's world and we just live in it, babe.