How to choose a specific entry from a roster?


I am a new learner for Kobo toolbox.
I have one issue how to write the syntax for below question. Can you please guide m?

Q1. How many children do your household have?

Q2. Please choose the youngest child in your household (based on the number of children in your household).
1. child 1
2. child 2

10.   child 10

Maybe this post discussed previously should help you solve your issue: