Not applicable to zoological parks:

Options

A. Collection of living plants for reference
B. Wild animals are kept under human care
C. Wild animals are kept in separate enclosures
D. All are true

Answer

**Step-by-Step Solution:**

1. **Understanding Zoological Parks**: Begin by defining what a zoological park (zoo) is. A zoological park is a facility where wild animals are kept under human care, typically in separate enclosures. The primary purpose of a zoo is to provide care for these animals and facilitate their study, education, and conservation.

2. **Analyzing the Options**: The question asks which option is not applicable to zoological parks. We have four options to consider.

3. **Evaluating Each Option**:
- **Option A: A collection of living plants for reference**: This option refers to a botanical aspect, which is not related to zoological parks. Zoos focus on animals, not plants. Therefore, this option is not applicable to zoological parks.
- **Option B: Wild animals are kept under human care**: This is a fundamental characteristic of zoological parks. Thus, this option is applicable.
- **Option C: Wild animals are kept in separate enclosures**: This is also true for zoological parks, as animals are housed separately for their safety and well-being. Hence, this option is applicable.
- **Option D: All are true**: Since Option A is not applicable, this statement cannot be true.

4. **Conclusion**: Based on the evaluation, the option that is not applicable to zoological parks is **Option A: A collection of living plants for reference**.

**Final Answer**: The correct answer is A.

---