Digestive system is complete where

Options

A. Digestive glands are present
B. Digestion occurs in the cavity
C. Both mouth and anus are present
D. Digestion occurs in the individual cells

Answer

To determine where the digestive system is complete, let's analyze the options given in the question step by step.

### Step 1: Understanding the Types of Digestive Systems
- A **complete digestive system** has two openings: a mouth for ingestion and an anus for egestion. This allows for a one-way flow of food through the digestive tract, enabling more efficient digestion and absorption of nutrients.
- An **incomplete digestive system** has only one opening, which serves both as the mouth and the anus. This means that food enters and exits through the same opening, which can limit the efficiency of digestion.

### Step 2: Analyzing the Options
1. **Digestive plants are present**: This option is incorrect. The presence of digestive glands or plants does not determine whether a digestive system is complete or incomplete.

2. **Cavity present**: This option is also incorrect. A cavity alone does not imply a complete digestive system.

3. **Both mouth and anus present**: This option is correct. The presence of both a mouth and an anus indicates a complete digestive system, as it allows for a continuous flow of food through the digestive tract.

4. **Digestion occurs in individual cells**: This option is incorrect. If digestion occurs in individual cells, it suggests an incomplete digestive system where food is broken down within cells rather than through a specialized digestive tract.

### Conclusion
The correct answer is that the digestive system is complete where **both mouth and anus are present**.