JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://andersmalmgren.github.io/Knockout.BindingConventions/src/Knockout.BindingConventions.js"></script>
<select data-name="items"></select>
<span data-name="selectedItem"></span>

JavaScript

TestViewModel = function() {
    this.items = ["1", "2", "3"];
    this.selectedItem = ko.observable();    
    
    this.canChangeSelectedItem = ko.computed(function() {
        return this.selectedItem() !== "2";
    }, this);
};

ko.applyBindings(new TestViewModel());