The animal with the longest gestation period is:

Options

A. shark
B. walrus
C. elephant
D. dog

Explanation

To solve the question regarding which animal has the longest gestation period, we can analyze the gestation periods of the animals listed in the options:

1. **Shark**: The gestation period for sharks can vary significantly, ranging from a few months to 3 years, but typically averages around 12 months.

2. **Walrus**: The gestation period for walruses is approximately 15 to 16 months.

3. **Elephant**: Elephants are known for having one of the longest gestation periods among land animals, which ranges from 18 to 22 months.

4. **Dog**: The gestation period for dogs is relatively short, lasting around 50 to 60 days.

Now, comparing these periods:

- Shark: ~12 months
- Walrus: ~15-16 months
- Elephant: 18-22 months
- Dog: ~50-60 days

From this comparison, it is evident that the elephant has the longest gestation period, which can last up to 22 months.

**Final Answer**: The animal with the longest gestation period is the **elephant**.