JSFiddle - React, Tailwind, and code Playground

HTML

<select name="unit">
  <option value="metric">Metric (cm)</option>
  <option value="imperial">Imperial (inches)</option>
 
</select>

 <label for="unit">test</label>

JavaScript

$("select[name = unit]").change(function()
        {
            var selected = $("option:selected", this).text();
           
            if(selected == "Metric (cm)")
            {
                $("label[for = unit]").text("mm");
            }
            else if(selected == "Imperial (inches)")
            {
                $("label[for = unit]").text("inches");  
            }
   });