Answer:
Option (B) is correct.
Explanation:
The prices of two inputs 1 and 2 are as follows:
w1 = $5
w2 = $2
Q = min{2x1, x2}
Cost is minimized when 2x1 = x2
140 = min{2x1, x2}
2x1 = 140
x1 = 70
x2 = 2x1 = 140
Total cost, C = w1.x1 + w2.x2
= 5x1 + 2x2
C($) = (5 × 70) + (2 × 140)
= 350 + 280
= $630