Final answer:
The hormone not secreted by the anterior pituitary among the options provided is Thyrotropin releasing hormone, as it is produced by the hypothalamus.
Step-by-step explanation:
The anterior pituitary gland is responsible for producing a variety of hormones that regulate various bodily functions. Four hormones mentioned as selectable answers include Follicle stimulating hormone (FSH), Leutinizing hormone (LH), Thyroid stimulating hormone (TSH), and Prolactin. However, out of these, the hormone that is not secreted by the anterior pituitary is D) Thyrotropin releasing hormone. This particular hormone is actually produced by the hypothalamus and it regulates the secretion of TSH from the anterior pituitary. The anterior pituitary does produce FSH, LH, TSH, and Prolactin, among other hormones.