Survey input required entry field not working

Hi Experts,

In my survey I have a question with four answers, those answers are input fields. In that one input field should make it mandatory, for that I have checked the Rqrd Entry Field option but while testing with the url its accepting empty value.

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In xml version of survey its showing mandatory="true" for that input field.

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But While submitting the survey its allowing empty value. am I doing anything wrong or any other way to make it mandatory? Kindly suggest me.

I have gone through with note 1387174 - Survey:Mandatory Input fields for the survey doesnt work also, still no use.

Please suggest me. Thank you in advance.

Thanks,

Vijay.