Cray fish is

Options

A. (a) crustacean
B. (b) edbile fish
C. (c) poisonous fish
D. (d) mammal.

Answer

### Step-by-Step Solution:

1. **Identify the Organism**: The question asks about crayfish. We need to understand what category of animal crayfish falls into.

2. **Review the Options**: The options provided are:
- A) Crustacean
- B) Edible fish
- C) Poisonous fish
- D) Mammal

3. **Determine the Classification**: Crayfish are classified as freshwater crustaceans. They belong to the phylum Arthropoda, which includes various invertebrates.

4. **Analyze the Characteristics**:
- Crayfish resemble lobsters, which further supports their classification as crustaceans.
- The edible parts of crayfish are primarily the tail and claws.

5. **Evaluate the Options**:
- **Option A (Crustacean)**: This is correct as crayfish are indeed crustaceans.
- **Option B (Edible fish)**: Incorrect, as crayfish are not fish; they are crustaceans.
- **Option C (Poisonous fish)**: While crayfish can contain toxins like DDT, they are not classified as poisonous fish.
- **Option D (Mammal)**: Incorrect, as crayfish do not belong to the mammal category.

6. **Conclusion**: Based on the classification and characteristics of crayfish, the correct answer is **A) Crustacean**.