Read the following statements and find out the incorrect statements.
a. The ventral portion of the midbrain consists mainly of four round swellings (lobes) called corpora quadrigemmina.
b. Midbrain and hindbrain form the brain stem.
c. Cerebellum consists of fibre tracts that interconnect different regions of brain.
d. The midbrain receives and integrates visual, lactile and auditory inputs.
e. Limbic system is concerned with olfaction and autonomic responses.

Options

A. a, c and d
B. b and e
C. a and c
D. a, c, d and e

Explanation

To identify the incorrect statements from the provided options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement A**: "The ventral portion of the midbrain consists mainly of four round swellings (lobes) called corpora quadrigemmina."
- **Analysis**: This statement is incorrect. The corpora quadrigemina are located in the dorsal portion of the midbrain, not the ventral portion.

2. **Statement B**: "Midbrain and hindbrain form the brain stem."
- **Analysis**: This statement is correct. The brain stem is composed of the midbrain, pons (part of the hindbrain), and medulla oblongata.

3. **Statement C**: "Cerebellum consists of fibre tracts that interconnect different regions of brain."
- **Analysis**: This statement is incorrect. It is the pons that consists of fiber tracts that interconnect different regions of the brain, not the cerebellum.

4. **Statement D**: "The midbrain receives and integrates visual, tactile, and auditory inputs."
- **Analysis**: This statement is correct. The midbrain is indeed responsible for processing these types of sensory information.

5. **Statement E**: "Limbic system is concerned with olfaction and autonomic responses."
- **Analysis**: This statement is correct. The limbic system is involved in olfaction (sense of smell) and various autonomic responses.

### Conclusion:
Based on the analysis:
- **Incorrect Statements**: A and C
- **Correct Statements**: B, D, and E

Thus, the incorrect statements are A and C.