Explanation:

Correct option:1

Solution:

Series follow the following pattern

25,    31,    34,     37,     43,      ?
      6       3        3         6 ( difference between them )

The pattern follows in second level is :

6 x 0.5 = 3

3 x 1 = 3

3 x 2 = 6

6 x 4 = 24

Then next term is 43+24 = 67

Hence 67 is the correct answer.