try this
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head >
<title></title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.0/knockout-min.js" type="text/javascript"></script>
</head>
<body>
<select data-bind="options: acSource, value:AcSource, optionsText: 'Name' , optionsValue: 'Value' "></select>
<script>
function myModel() {
this.acSource = ko.observableArray([{ Name: "EB", Value: 1 }, { Name: "DG", Value: 2 }, { Name: "EB & DG", Value: 3 }]);
this.AcSource = ko.observable();
}
ko.applyBindings(new myModel());
</script>
</body>
</html>