Explanation:

The given number series is 1, 3, 10, 41, 206, ?

It follows a pattern that,

1

1 x 2 + 1 = 3

3 x 3 + 1 = 10

10 x 4 + 1 = 41

41 x 5 + 1 = 206

206 x 6 + 1 = 1237

Hence, the next number in the given number series is 1237.

Henc,e option 1 is the correct answer.