Match List-I with List-II. 

List-I	List-II
A. Progesterone	I. Pars intermedia
B. Relaxin	II. Ovary
C. Melanocyte stimulating hormone	III. Adrenal Medulla
D. Catecholamines	IV. Corpus luteum

Choose the correct answer from the options given below:

The correct answer is A-IV, B-II, C-I, D-III

Explanation:

A. Progesterone - IV (Corpus luteum):

• Progesterone is a steroid hormone primarily produced by the corpus luteum in the ovaries.
• It plays a critical role in regulating the menstrual cycle and maintaining pregnancy by preparing the uterine lining for implantation of the fertilized egg.
• During pregnancy, the placenta also produces progesterone to support fetal development.

B. Relaxin - II (Ovary):

• Relaxin is a hormone secreted mainly by the ovary, specifically by the corpus luteum, during pregnancy.
• It helps relax the ligaments in the pelvis and softens the cervix to prepare for childbirth.
• It also plays a role in inhibiting uterine contractions during early pregnancy.

C. Melanocyte-Stimulating Hormone (MSH) - I (Pars intermedia):

• MSH is produced by the pars intermedia of the pituitary gland (a part of the intermediate lobe of the pituitary).
• It regulates the production and release of melanin in the skin, which affects pigmentation.

D. Catecholamines - III (Adrenal Medulla):

• Catecholamines such as adrenaline (epinephrine) and noradrenaline (norepinephrine) are produced by the adrenal medulla.
• These hormones are part of the body's response to stress ("fight-or-flight" response), increasing heart rate, blood pressure, and glucose levels.
• Catecholamines also stimulate the breakdown of glycogen resulting in an increased concentration of glucose in blood. In addition, they also stimulate the breakdown of lipids and proteins.