JSFiddle: https://jsfiddle.net/ypcrumble/kj2b8dk7/4/

The following code is a simplified version of a problem I'm facing in a React 12.2 app using JSX, on IE 10. Specifically, the line

var postData = rsvp.currentTarget.selectedOptions[0].value;

fails in IE. It works in Chrome and Firefox. First, why does this fail in IE10, and second, how can I adjust the code to make it work?

var Hello = React.createClass({
    getInitialState: function() {
        return {parsed: false};
    },
    _onRSVP: function(rsvp) {
        console.log(rsvp);
        var postData = rsvp.currentTarget.selectedOptions[0].value;
        this.setState({parsed: true});
        alert(postData);
    },
    render: function() {
        var parsing = "parsing worked";
        return (
        <div>
        <select            
            onChange={this._onRSVP}>
            <option value="----">----</option>
            <option value="Yes">Yes</option>
            <option value="No">No</option>
        </select>
        <p>
        { this.state.parsed ?
        {parsing}
        : null}
        </p>
        </div>
        );
    }
});

React.render(<Hello name="World" />, document.getElementById('container'));