react应用程序，根据下拉选项加载组件

import React, { useState } from 'react';

const ComponentA = () => <div>Component A</div>;
const ComponentB = () => <div>Component B</div>;
const ComponentC = () => <div>Component C</div>;

const App = () => {
  const [selectedOption, setSelectedOption] = useState('');

  const handleOptionChange = (event) => {
    setSelectedOption(event.target.value);
  };

  let componentToRender;

  switch (selectedOption) {
    case 'optionA':
      componentToRender = <ComponentA />;
      break;
    case 'optionB':
      componentToRender = <ComponentB />;
      break;
    case 'optionC':
      componentToRender = <ComponentC />;
      break;
    default:
      componentToRender = null;
  }

  return (
    <div>
      <select value={selectedOption} onChange={handleOptionChange}>
        <option value="">Select an option</option>
        <option value="optionA">Option A</option>
        <option value="optionB">Option B</option>
        <option value="optionC">Option C</option>
      </select>
      {componentToRender}
    </div>
  );
};

export default App;