Something like this:
Question 1: What is a survey
answer one
answer two
other: _______
See T224552: [SPIKE] Assess risk for various quicksurvey improvements for more info.
Update
Unfortunately, we cannot use the solution proposed by the spike, i.e. the combination of radio buttons and a text input, because of a long standing bug: T177617: Not able to type in RadioSelectWidget with text input in a label in OOUI. I'll try to find another solution.