Select the correct statement regarding the menstrual cycle .

Options

A. A rapid secretion of FSH leads to the rupture of the Graafian follicle and the ovum is released
B. Estrogen secreted by the corpus luteum is necessary for the maintenance of the endometrium.
C. During the follicular phase , the primary follicles change into the Graafian follicle, which is transformed into corpus luteum post ovulation.
D. All of the above

Answer

To solve the question regarding the menstrual cycle, we need to evaluate each of the provided statements and determine which one is correct. Here’s a step-by-step breakdown of the solution:

### Step 1: Analyze the First Statement
The first statement claims that a rapid secretion of FSH leads to the growth of the Graafian follicle and the release of the ovum.

- **Evaluation**: While FSH (Follicle Stimulating Hormone) does stimulate the growth of follicles, it is actually the surge of LH (Luteinizing Hormone) that triggers ovulation, leading to the release of the ovum from the Graafian follicle. Therefore, this statement is incorrect.

### Step 2: Analyze the Second Statement
The second statement suggests that estrogen secreted by the corpus luteum is necessary for the endometrium.

- **Evaluation**: This statement is incorrect because the corpus luteum primarily secretes progesterone, not estrogen. Progesterone is the hormone responsible for maintaining the endometrium during the menstrual cycle. Hence, this statement is also incorrect.

### Step 3: Analyze the Third Statement
The third statement states that during the follicular phase, the primary follicles change into the Graafian follicle, which is transformed into the corpus luteum post-ovulation.

- **Evaluation**: This statement is correct. During the follicular phase, primary follicles develop into secondary follicles and then into Graafian follicles. After ovulation, the ruptured Graafian follicle transforms into the corpus luteum. Thus, this statement accurately describes the process.

### Step 4: Analyze the Fourth Statement
The fourth option states "all of the above."

- **Evaluation**: Since the first two statements are incorrect, this option cannot be correct.

### Conclusion
The only correct statement regarding the menstrual cycle is the third one: "During the follicular phase, the primary follicle changes into the Graafian follicle, which is transformed into corpus luteum post-ovulation."

### Final Answer
**The correct answer is the third statement.**

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