The first, second and fourth numbers in a proportion are 31, 12 and 156 respectively.

Correct option is B

Given:
First = 31
Second = 12
Fourth = 156
Formula Used:
In proportion: First : Second = Third : Fourth
Solution:
31 : 12 = x : 156
31 × 156 = 12x
x = $$\frac{31 × 156} {12}$$​​
x = 403