Select the correct statements :-

Options

A. Sexual reproduction involves the formation and fusion of gametes
B. Sexual reproducrion is complex and slower process as compared to asexual reproduction
C. Most of the higher animals reproduce almost entirely by sexual method
D. All of the above

Answer

To solve the question of selecting the correct statements regarding sexual reproduction, we will analyze each statement provided in the context of biological principles.

### Step-by-Step Solution:

1. **Understanding Sexual Reproduction**:
- The first statement is that sexual reproduction involves the formation and fusion of gametes.
- **Analysis**: This statement is true. Sexual reproduction indeed requires the formation of male (sperm) and female (egg) gametes, which then fuse during fertilization to form a zygote.

2. **Comparing Sexual and Asexual Reproduction**:
- The second statement claims that sexual reproduction is a complex and slower process compared to asexual reproduction.
- **Analysis**: This statement is also true. Sexual reproduction typically involves more steps, such as gamete formation and fertilization, which makes it more complex and time-consuming than asexual reproduction, which can occur rapidly and without the need for gametes.

3. **Reproductive Methods in Higher Animals**:
- The third statement asserts that most higher animals reproduce almost entirely by the sexual method.
- **Analysis**: This statement is true as well. Higher organisms, due to their complex body structures and reproductive systems, predominantly engage in sexual reproduction.

4. **Conclusion**:
- Since all three statements are true, the correct answer to the question is option D: "All of the above."

### Final Answer:
The correct statements are:
- A. Sexual reproduction involves the formation and fusion of gametes.
- B. Sexual reproduction is a complex and slower process compared to asexual reproduction.
- C. Most of the higher animals reproduce almost entirely by the sexual method.
- Therefore, the answer is D: All of the above.

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