Systematic enumeration of animal species occurring in a given region is called :
(a) flora
(b) fauna
(c) monograph
(d) manual

Options

A. flora
B. fauna
C. monograph
D. manual

Explanation

To solve the question "Systematic enumeration of animal species occurring in a given region is called:", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understand the Question**: The question asks for the term that describes the systematic listing of animal species in a specific area.

2. **Evaluate Option A - Flora**:
- Flora refers to the plant species that are found in a particular region. Since the question specifically mentions animal species, flora is not the correct answer.

3. **Evaluate Option B - Fauna**:
- Fauna refers to the animal species that inhabit a particular region. This matches the description in the question, making this a strong candidate for the correct answer.

4. **Evaluate Option C - Monograph**:
- A monograph is a detailed written study of a single specialized subject or an aspect of it. It does not specifically refer to the enumeration of species, so this option is not correct.

5. **Evaluate Option D - Manual**:
- A manual is a guide or handbook that provides instructions or protocols for a specific task. It does not pertain to the enumeration of species, thus it is not the correct answer.

6. **Conclusion**: After evaluating all options, the correct answer is **(b) fauna**, as it directly refers to the systematic enumeration of animal species in a given region.

### Final Answer:
(b) fauna