Dropdown field is showing "Other" option

Dropdown field is showing "Other" option

We have a Creator application where we are tracking Customer's visit activity. 

Currently the Activity dropdown field has 4 options:
  • Buy - Yes
  • Buy - No
  • Decision Pending
  • Return/Exchange
When adding a record, we get the desired 4 options. However, on the edit screen, Creator shows an additional option - "Other" as shown in the image.

We suspect it has something to do with the On Load screen of that form but can't really figure out whats the issue.

Any help would be appreciated.

Thanks!