Array
(
 [subject_id] => Array
    (
        [0] => 1
        [1] => 1
    )

[question] => Array

    (
        [0] => test
        [1] => test2
    )

[option1] => Array
    (
        [0] => test
        [1] => test2
    ) )

$this->db->insert_batch('mytable', $data);