Natural methods of contraception work on the principle of avoiding chances of ovum and sperm meeting. It includes
(A) Periodic abstinence
(B) Withdrawl
(C ) Coitus interrupts
(D) Lactational ammenorrhoea

Options

A. A and B only
B. B and C only
C. A,B and C
D. A,B,C and D

Answer

To solve the question regarding natural methods of contraception that work on the principle of avoiding the chances of ovum and sperm meeting, we will analyze each option provided:

### Step-by-Step Solution:

1. **Understanding Natural Methods of Contraception**:
- Natural methods of contraception are designed to prevent fertilization by avoiding the meeting of sperm and ovum.

2. **Option A: Periodic Abstinence**:
- This method involves avoiding sexual intercourse during the ovulation phase of the menstrual cycle. Couples track the menstrual cycle to identify fertile days and abstain from coitus during that time. This method effectively reduces the chances of sperm meeting the ovum.

3. **Option B: Withdrawal**:
- Also known as the withdrawal method, this involves the male partner withdrawing his penis from the vagina before ejaculation. While this method can reduce the chances of pregnancy, it is not foolproof as pre-ejaculatory fluid may contain sperm.

4. **Option C: Coitus Interruptus**:
- This term is often used interchangeably with the withdrawal method. It also involves the male partner pulling out before ejaculation. Similar to the withdrawal method, it carries a risk of pregnancy due to potential sperm in pre-ejaculatory fluid.

5. **Option D: Lactational Amenorrhea**:
- This method is based on the natural infertility that occurs when a woman is exclusively breastfeeding. It is effective for the first 2-3 months postpartum when menstruation has not resumed, thus significantly reducing the chances of ovulation and fertilization during this period.

6. **Conclusion**:
- All four options (A, B, C, and D) are natural methods of contraception aimed at preventing the meeting of sperm and ovum. However, the effectiveness varies, with lactational amenorrhea being the most reliable during the specified period.

### Final Answer:
The natural methods of contraception that work on the principle of avoiding the chances of ovum and sperm meeting include:
- (A) Periodic abstinence
- (B) Withdrawal
- (C) Coitus Interruptus
- (D) Lactational Amenorrhea