_________ fertilization usually takes place in aquatic animals, such as fish and frogs, or in animals that live near waterbodies.

Options

A. External
B. Internal
C. Both (a) and (b)
D. Bisexual

Explanation

**Step-by-Step Solution:**

1. **Understanding the Types of Fertilization**: There are two main types of fertilization in animals: external and internal.

2. **Defining External Fertilization**: External fertilization occurs when the male and female gametes fuse outside the female's body. This process typically happens in aquatic environments.

3. **Examples of External Fertilization**: Fish and frogs are prime examples of animals that utilize external fertilization. In these species, both male and female gametes are released into the water, where fertilization occurs.

4. **Defining Internal Fertilization**: In contrast, internal fertilization occurs when the fusion of gametes takes place inside the female's body. This is common in terrestrial animals, including humans.

5. **Conclusion**: Since the question specifically mentions aquatic animals like fish and frogs, the type of fertilization that occurs in these animals is external fertilization.

6. **Final Answer**: Therefore, the correct answer to the question is "external."

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