Viroids are

Options

A. generally present in animal viruses
B. obligate parasites
C. infectious RNA particles
D. both (2) and (3)

Answer

**Step-by-Step Solution:**

1. **Understanding Viroids**: Viroids are a type of pathogen that primarily affect plants. They are not viruses but are similar in some ways.

2. **Characteristics of Viroids**:
- Viroids are **obligate parasites**, meaning they can only reproduce within a host cell.
- They consist of **small, single-stranded circular RNA** particles, which are much simpler than viruses.
- Viroids do not have a **capsid** (the protein coat that surrounds viruses) or an outer envelope.

3. **Reproduction**: Like viruses, viroids can only reproduce inside a host cell, which is a crucial characteristic that defines them as pathogens.

4. **Infectious Nature**: Viroids are known to have **infectious RNA particles**, which contribute to their ability to cause disease in plants.

5. **Evaluating Options**:
- The first option states that viroids are generally present in animal viruses, which is incorrect since they are primarily plant pathogens.
- The second option states that viroids are obligate parasites, which is correct.
- The third option states that they have infectious RNA particles, which is also correct.
- The fourth option combines the second and third options, which are both correct.

6. **Conclusion**: Based on the characteristics and evaluation of the options, the correct answer is that viroids are obligate parasites and have infectious RNA particles. Therefore, the correct choice is option 4, which states that both statements 2 and 3 are correct.

---