JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app ng-controller="myCtrl">
 <select ng-model="data" ng-options="opt as opt.label for opt in units ">

</div>

JavaScript

function myCtrl ($scope) {
    $scope.units = [
        {'id': 10, 'label': 'test1'},
        {'id': 27, 'label': 'test2'},
        {'id': 39, 'label': 'test3'},
    ]

           $scope.data= $scope.units[0]; // Set by default the value "test1
};