Make question (input text) mandatory based on previous answer

Hello, my situation is like this.


Q1. I would like to be notified via

• SMS
• Email

Then later
Q5. Please enter your email address: [text box]

I want to make Q5 mandatory if the answer to Q1 is Email. I'm already aware of Relevance and it doesn't work here because I still want to collect the email address even if Q1's answer is SMS. Therefore, branching won't work.

Another option I considered is to have 2 email fields (one for SMS - not mandatory, one for Email-mandatory). This works but is too much of a hack and I would only use it as the last resort.

Beside those 2 methods above, is there a cleaner way to accomplish what I need?

Thanks in advance.

Thank you, DenisChenu! That works perfectly.