如何将默认单选按钮设置为选中，并在反应式表单中知道选中了单选按钮组中的哪个单选按钮？

<form [formGroup]="myForm">
  <label>
    <input type="radio" formControlName="option" value="option1"> Option 1
  </label>
  <label>
    <input type="radio" formControlName="option" value="option2"> Option 2
  </label>
  <label>
    <input type="radio" formControlName="option" value="option3"> Option 3
  </label>
</form>

import { Component } from '@angular/core';
import { FormGroup, FormControl } from '@angular/forms';

@Component({
  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
})
export class MyComponent {
  myForm: FormGroup;

  constructor() {
    this.myForm = new FormGroup({
      option: new FormControl('option1') // 设置默认选中的值为option1
    });

    this.myForm.get('option').valueChanges.subscribe(value => {
      console.log('选中的单选按钮值为：', value);
    });
  }
}