Allows multiple questions to be opened on FAQ Accordion

I want to modify my code where it allows me to open multiple questions at once, because in this code it only opens one. when I opened another question, the previous one closes.

import React, { useState } from "react";
import "./faq.css";

function Faq() {
  const [selected, setSelected] = useState(null);

  const toggle = (id) => {
    if (selected === id) {
      return setSelected(null);
    }

    setSelected(id);
  };



  return (
    <div className="container">
      <h2>Frequently Asked Questions</h2>
      <div className="questions">
        {Questions.map((question) => (
          <div key={question.id}>
            <h4>
              {question.title}
              <button onClick={() => toggle(question.id)}>
                {selected === question.id ? "X" : "+"}
              </button>
            </h4>
            <p
              className={selected === question.id ? "question-info" : "hidden"}
            >
              {question.info}
            </p>
          </div>
        ))}
      </div>
    </div>
  );
}

export default Faq;

Here is my code and I can’t solve this problem