JSFiddle - React, Tailwind, and code Playground

HTML

<select class="assUnit">
    <option>Unit1</option>
    <option>Unit2</option> 
    <option>Unit3</option> 
</select>

 <select class="assUnit">
    <option>Unit10</option>
    <option>Unit2</option> 
    <option>Unit33</option> 
</select> 

<input type="button" id="my_button" value="test me"/>

JavaScript

$(function(){
    $('#my_button').click(function(){
        var unitName = "Unit2";
        $('.assUnit').find('option:contains('+unitName+')').remove();
    });
    
});