Which one of the following statements is correct ?
(a) Benign tumours spread to distant sites.
(b) Heroin accelerates body functions.
(c) Malignant tumours exhibit metastasis.
(d) Patients who have undergone surgery are given cannabinoids to relieve pain.

Options

A. Benign tumours spread to distant sites.
B. Heroin accelerates body functions.
C. Malignant tumours exhibit metastasis.
D. Patients who have undergone surgery are given cannabinoids to relieve pain.

Explanation

To solve the question, we will evaluate each of the provided statements one by one to determine which one is correct.

### Step-by-Step Solution:

1. **Evaluate Statement (a)**: "Benign tumors spread to distant sites."
- **Analysis**: Benign tumors are non-cancerous growths that do not spread to other parts of the body. They remain localized in one area and do not invade surrounding tissues or metastasize.
- **Conclusion**: This statement is **false**.

2. **Evaluate Statement (b)**: "Heroin accelerates body functions."
- **Analysis**: Heroin is an opioid and acts as a depressant on the central nervous system. It slows down body functions rather than accelerating them.
- **Conclusion**: This statement is **false**.

3. **Evaluate Statement (c)**: "Malignant tumors exhibit metastasis."
- **Analysis**: Malignant tumors are cancerous and have the ability to spread to other parts of the body through the bloodstream or lymphatic system. This process is known as metastasis.
- **Conclusion**: This statement is **true**.

4. **Evaluate Statement (d)**: "Patients who have undergone surgery are given cannabinoids to relieve pain."
- **Analysis**: While cannabinoids may have some use in pain management, opioids are the primary medications given to patients post-surgery for pain relief due to their analgesic properties. Cannabinoids are more commonly associated with their psychoactive effects.
- **Conclusion**: This statement is **false**.

### Final Conclusion:
The correct statement among the options provided is **(c) Malignant tumors exhibit metastasis**.