<!DOCTYPE html> <html lang="en"> <head> <title>HTML Select Box with Grouped Options</title> </head> <body> <form> <select> <optgroup label="Fruits"> <option value="apple">Apple</option> <option value="banana">Banana</option> </optgroup> <optgroup label="Colors"> <option value="red">Red</option> <option value="green">Green</option> </optgroup> </select> </form> </body> </html>