Which on eis the characteristic of class crustacea ?

Options

A. Cephalothorax with two pairs of antennae
B. Gills and green glands
C. Both A and B
D. Cephalothorax with one pair of antennae.

Answer

To determine the characteristics of the class Crustacea, follow these steps:

### Step-by-Step Solution:

1. **Identify the Class**: Crustacea is a class within the phylum Arthropoda. It includes various aquatic animals such as crabs, lobsters, and shrimp.

2. **Examine the Options**: The question provides four options regarding the characteristics of Crustacea:
- Option 1: Cephalothorax with two pairs of antennae
- Option 2: Gills and green glands
- Option 3: Both A and B
- Option 4: Cephalothorax with one pair of antennae

3. **Analyze Option 1**:
- Crustaceans have a body that is divided into two main parts: the cephalothorax (which combines the head and thorax) and the abdomen.
- They possess two pairs of antennae, which is a defining characteristic of this class.

4. **Analyze Option 2**:
- Crustaceans have gills for respiration, which allows them to extract oxygen from water.
- They also have green glands (or antennal glands) that function in excretion.

5. **Combine Findings**:
- Both Option 1 (cephalothorax with two pairs of antennae) and Option 2 (gills and green glands) are correct characteristics of Crustacea.

6. **Select the Correct Answer**:
- Since both characteristics are true, the correct answer is Option 3: Both A and B.

### Final Answer:
The characteristic of class Crustacea is that they have a cephalothorax with two pairs of antennae and gills along with green glands. Therefore, the correct option is **Option 3: Both A and B**.

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