Answer : Option D

Explanation :

l : b = 3 : 2 ------------------------------------------(Equation 1)
Perimeter of the rectangular park
= Distance travelled by the man at the speed of 12 km/hr in 8 minutes
= speed × time = 12 × ⁸/₆₀ (∵ 8 minute = 8/₆₀ hour)
= ⁸/₅ km = ⁸/₅ ×1000 m = 1600 m
Perimeter = 2(l + b)
=> 2(l + b) = 1600
=> l + b = ¹⁶⁰⁰/₂ = 800 m ---------------------------(Equation 2)
From (Equation 1) and (Equation 2)
l = 800 × ³/₅ = 480 m
b = 800 × ²/₅ = 320 m (Or b = 800 - 480 = 320m)
Area = lb = 480 × 320 = 153600 m²