Answer:
C) 72 ft²
Explanation:
Surface area of a prism can be found using the general formula: 
SA = 2ab + 2ac + 2bc, where 'a', 'b' and 'c' are the measurements of the prism
a = 1.8 ≈ 2ft 
b = 2.9 ≈ 3ft
c = 5.7 ≈ 6ft
SA = 2(2*3) + 2(2*6) + 2(3*6) 
SA = 12 + 24 + 36 
SA ≈ 72 ft²