JSFiddle - React, Tailwind, and code Playground

HTML

<select class="estados" name="estado">
    <option class="op1" value="">1</option>
    <option class="op2" value="">2</option>
    <option class="op3" value="">3</option>
</select>
<input type="reset" class="bt" value="refazer" />

JavaScript

$(".bt").on("click", function () {
    $("select.estados option").each(function (i) {
        $(this).removeAttr("selected");
        if (i == 0) this.selected = true; // onde o "i" é o index desse select, começando em zero
    });
});