During mid-cycle (menstruation cycle) :
A. LH and FSH attain a peak level
B. Ovulation occurs
C. Maximum progesterone level in blood
D. Regression of corpus luteum occurs.

Options

A. A, B
B. A, B, C
C. C, D
D. A, B, C, D

Answer

To solve the question regarding events during the mid-cycle of the menstruation cycle, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding the Menstrual Cycle**:
- The menstrual cycle typically lasts about 28 days and can be divided into several phases: the follicular phase, ovulation, the luteal phase, and menstruation.
- The mid-cycle refers to the ovulation phase, which occurs around the 14th day of the cycle.

2. **Analyzing Each Option**:
- **Option A: LH and FSH attain a peak level**:
- During the mid-cycle, specifically around day 14, there is a surge in Luteinizing Hormone (LH) and Follicle Stimulating Hormone (FSH). This surge is crucial for triggering ovulation.
- **Conclusion**: This statement is true.

- **Option B: Ovulation occurs**:
- Ovulation is the process where a mature egg is released from the ovary, and it occurs around the same time as the LH surge, typically on day 14 of the cycle.
- **Conclusion**: This statement is true.

- **Option C: Maximum progesterone level in blood**:
- Progesterone levels peak during the luteal phase, which occurs after ovulation. Therefore, at mid-cycle (day 14), progesterone levels are not at their maximum; they rise after ovulation.
- **Conclusion**: This statement is false.

- **Option D: Regression of corpus luteum occurs**:
- The corpus luteum forms after ovulation and begins to regress if pregnancy does not occur, typically around day 20 of the cycle. Therefore, this does not happen during the mid-cycle.
- **Conclusion**: This statement is false.

3. **Final Answer**:
- Based on the analysis, the correct options during mid-cycle are:
- A. LH and FSH attain a peak level (True)
- B. Ovulation occurs (True)
- Therefore, the correct answer is **Option 1** (A and B are correct).