Explanation:

- Let's analyze the given series: 50, 86, ?, 127, 136, 140, 141.

- Check the difference between each consecutive pair of numbers.

- The difference between 50 and 86 is 36.

- The difference between 127 and 136 is 9, between 136 and 140 is 4, and between 140 and 141 is 1.

- We observe that the difference seems to be decreasing, likely alternatively more specific.

- Checking difference, between 86 and 127 is 41. However, if we assume there is a decreasing pattern, the difference between 86 and 111 is 25, which fits as decreasing step from 36.

- Option 3 - 111 is the missing number.