I am going to make a list of options. Which the correct form to use as an option: 'other' or 'others'? The option may contain several members.
No matter if the option contains one or several members, the term to use is
Firstly, this is the term most commonly used.
Also, the reason seems to be that the word 'other' here is not a noun but an adjective: it does not refer to 'the other' but the set of 'other options'. As other is not a noun here, it cannot be pluralized.
It depends what you are asking.
What is your requirement? If two other unlisted modes of transport should be entered in the last choice (say helicopter and skateboard), then that could say Others, which would indicate that more than one can be entered.
On the other hand, if you want each of the "other" choices to be specified separately, it would be better to indicate that: