From which one of the following,the melatonin is derived?

The pineal gland secretes which hormones?
$I. Serotonin$ $II. ACTH$ $III. MSH$ $IV. PRL$ $V. Melatonin$ $VI. FSH$
The correct option is:

Melatonin is secreted by ..........

Where is the pineal gland located?

The pineal gland originates from the:

"Pinealocytes" are found in which of the following?