Which of the following has the longest gestation period:-

Options

A. Man
B. Cat
C. Dog
D. Elephant

Explanation

To determine which of the given options has the longest gestation period, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understand the Concept of Gestation Period**:
- The gestation period is the time duration between fertilization and the birth of the offspring (parturition). Different species have varying gestation periods.

2. **List the Options**:
- The options provided are:
- A) Man
- B) Cat
- C) Dog
- D) Elephant

3. **Research the Gestation Periods for Each Option**:
- **Man**: The average gestation period is approximately 266 to 280 days.
- **Cat**: The gestation period is around 58 to 67 days.
- **Dog**: The gestation period is similar to that of cats, approximately 58 to 68 days.
- **Elephant**: The gestation period is significantly longer, ranging from 624 to 641 days.

4. **Compare the Gestation Periods**:
- Man: 266 to 280 days
- Cat: 58 to 67 days
- Dog: 58 to 68 days
- Elephant: 624 to 641 days

5. **Identify the Longest Gestation Period**:
- Upon comparing the gestation periods, it is clear that the elephant has the longest gestation period, which is 624 to 641 days.

6. **Conclusion**:
- Therefore, the organism with the longest gestation period among the options is the **Elephant** (Option D).

### Final Answer:
- The correct answer is **D) Elephant**.