My ASPNET code automatically correcting wrongly HTML tags. It just normal variable string. i tried put wrong <option></optionx> and it automatically convert to correct form <option></option> also i can't put <span> between option like <option value="example">sample <span>active</span></option>

here's the snapshot of my code https://i.imgur.com/pdzCVam.png

is this normal on ASPNET ?

edit: i use

<% Response.Write(getRep()); %> 

on ASPX page to output the string. it same that response.write change everything when output value