To solve this problem, we need to match the items in Column I with the appropriate descriptions in Column II. Let's analyze each item:$\newline \bullet$a. Placenta:$\newline$ - The placenta is an organ that develops in the uterus during pregnancy. It produces several hormones, including Human Chorionic Gonadotropin (hCG).$\newline$ - This matches with ii.$\newline \bullet$b. Zona pellucida:$\newline$ - The zona pellucida is a glycoprotein layer surrounding the plasma membrane of mammalian oocytes.$\newline$ - This matches with iii, as it is a layer of the ovum.$\newline \bullet$c. Bulbo-urethral glands:$\newline$ - These glands secrete a fluid that lubricates the urethra and neutralizes traces of acidic urine in the urethra.$\newline$ - This matches with iv, as it is involved in the lubrication of the penis.$\newline \bullet$d. Leydig cells:$\newline$ - Leydig cells are found in the testes and are responsible for the production of androgens, such as testosterone.$\newline$ - This matches with i.$\newline$Now, let's match the items from Column I with Column II:$\newline a \rightarrow ii, b \rightarrow iii, c \rightarrow iv, d \rightarrow i \newline$This corresponds to Option 3.