class DropList extends React.Component {
	constructor(props){
	  super(props);
    this.state = {
      options: [1,2,3]
    }
  }
  render() {
    return <select>{this.state.options.map((option, idx) => <option key={idx}>{option}</option>)}</select>
  }
}
ReactDOM.render(<DropList />, document.getElementById('root'))