A cistern 4m long and 2 m wide contains water up to a depth of 1 m 25 cm. The total area of the wet surface is:	Choose the correct option.
A) 23 m 2	B) 20 m 2	C) 52 m 2	D) 24 m 2	E) 55 m 2

Rationale: "area of the wet surface = [ 2 ( lb + bh + lh ) - lb ] = 2 ( bh + lh ) + lb = [ 2 ( 2 x 1.25 + 4 x 1.25 ) + 4 x 2 ] m 2 = 23 m 2 . answer : a"
Answer: A