How to link free answers to a question?

Question

MySQL

Three Doctrine entities are given.
Answers to the questions of the questionnaireAnswer :

/**
 * @ORM\Entity(repositoryClass="App\Repository\AnswerRepository")
 */
class Answer
{
    /**
     * @Groups({"answer"})
     * @ORM\Column(type="string", length=255, nullable=true)
     */
    private $text;

    /**
     * @Groups({"answer"})
     * @ORM\Column(type="integer", nullable=true)
     */
    private $num;

    /**
     * @Groups({"answer"})
     * @ORM\Column(type="boolean", nullable=true)
     */
    private $yn;

    /**
     * @Groups({"answer"})
     * @ORM\ManyToMany(targetEntity="App\Entity\Question", inversedBy="answers")
     */
    private $question;

    /**
     * @Groups({"answer"})
     * @ORM\ManyToMany(targetEntity="App\Entity\Options", inversedBy="answers")
     */
    private $options;
    // ...
}

Options for answering the questions of the questionnaireOptions :

class Options
{
    /**
     * @ORM\ManyToMany(targetEntity="App\Entity\Answer", mappedBy="options")
     */
    private $answers;
    // ...
}

And the essence Questionwith the questions of the questionnaire .

/**
     * @ORM\ManyToMany(targetEntity="App\Entity\Answer", mappedBy="question")
     */
    private $answers;

POST request:

{
    "text": [
        "text",
        "another text"
    ],
    "num": [
        "",
        "1"
    ],
    "yn": [
        "",
        "1"
    ],
    "options": [
        "3",
        "2",
        "1"
    ],
    "question": [
        "1",
        "2"
    ]
}

The form:

$answer = new Answer();
        $builder
            ->add('text')
            ->add('num')
            ->add('yn')
            ->add('question')
            ->add('options')
        ;

Database model:
Fields num, ynand textare needed to answer the question if the answer is not prepared in advance ( <input type="text">).
Optionsand Question- there is a connection. Fields num, ynand text(no binding to options) - no connection. How can they be linked to questions and answers? Now they are simply added to the table Answer.