Step-by-step Solution:

The series is: 2, 5, 10, 17, 26, 38, 50, 65.

Differences between consecutive terms:

• 5 - 2 = 3
• 10 - 5 = 5
• 17 - 10 = 7
• 26 - 17 = 9
• 38 - 26 = 12
• 50 - 38 = 12
• 65 - 50 = 15

The differences should follow an arithmetic progression with a common difference of 2: 3, 5, 7, 9, 11, 13, 15.

The expected number after 26 is 26 + 11 = 37, but the given number is 38. Therefore, 38 is the wrong number.

Answer: (D) 38