Create checkbox for multiple choice - PHP

I want change an inputText to a CheckBox for multiple choices like this.

I did it but, it dosen't work fine. According this guide enter link description here I should set expanded to true and multiple also to true This following the code:

->add('Article', ChoiceType::class, 
    array(
        'choices' => 
            array('A' => 'B',
                        'B' => 'B',
                        'C' => 'C',
                        'D' => 'D',
                        'OTHERS' => 'OTHERS'
            ),
        'required' => false,
        'multiple' => true,
        'expanded' => true
    )
);

This is the screen sheet:

How can I change it to display a checkbox like in the picture 1 ? Thank you.