Given number series: 4, 9, 20, 44, ?

To find the missing number in the series, let's try to identify the pattern or rule followed in the given series:

1. Difference between consecutive terms:
- The difference between the first and second term is 9 - 4 = 5.
- The difference between the second and third term is 20 - 9 = 11.
- The difference between the third and fourth term is 44 - 20 = 24.

We can observe that the differences between consecutive terms are increasing by 6 each time.

2. Multiply the differences by the position of the term:
- The difference between the second and third term is 11, and it is the second term. So, 11 * 2 = 22.
- The difference between the third and fourth term is 24, and it is the third term. So, 24 * 3 = 72.

We can see that the differences are multiplied by the position of the term.

3. Add the result to the previous term:
- The second term (9) + the result (22) = 31.
- The third term (20) + the result (72) = 92.

We can observe that the result is added to the previous term to get the next term in the series.

Using the above pattern, we can find the missing number in the series:

- The fourth term is 44, and the difference between the third and fourth term is 24. So, the result will be 24 * 4 = 96.
- Adding the result (96) to the fourth term (44) gives us the missing number: 44 + 96 = 140.

Since none of the options provided matches the missing number 140, it seems there might be an error in the given question or options.