Embryology is

Options

A. Development of embryo only
B. Mode of gametophyte formation
C. Sporogenesis and fertilization
D. Sporogensis, fertilization and embryogenesis.

Answer

**Step-by-Step Solution:**

1. **Understanding Embryology**:
- Embryology is the branch of biology that studies the formation and development of embryos. It encompasses all processes related to the embryo's development from fertilization to the formation of a fully developed organism.

2. **Analyzing the Options**:
- **Option A**: "Development of embryo only" - This option is too narrow as it only refers to one aspect of embryology.
- **Option B**: "Mode of gametophyte formation" - This is also incorrect as it focuses solely on gametophyte formation, which is just a part of the reproductive process.
- **Option C**: "Sporogenesis and fertilization" - While this includes important processes, it does not encompass the entire development of the embryo.
- **Option D**: "Sporogenesis, fertilization, and embryogenesis" - This option is comprehensive as it includes the formation of spores, the fertilization process, and the subsequent development of the embryo.

3. **Conclusion**:
- Based on the analysis, the correct answer is **Option D**: "Sporogenesis, fertilization, and embryogenesis" as it covers all aspects of embryology.