Please help me

Dear student,
Option 4 is correct.
The non-iodised thyroid hormone is calcitonin.
It is secreted by parafollicular cells in response to hypercalcemia and is antagonist to para thyroid hormone.

Hope this information will clear your doubts about topic.

If you have any more doubts just ask here on the forum and our experts will try to help you out as soon as possible.

Regards