With reference to carbon nanotubes, consider the following statements1. They can be used as carriers of drugs and antigens in the human body.2. They can be made into artificial blood capillaries for an injured part of the human body.3. They can be used in biochemical sensors.4. Carbon nanotubes are biodegradable.Which of the statements given above are correct?

• A. 1 and 2 only
• B. 2, 3 and 4 only
• C. 1, 3 and 4 only
• D. 1, 2, 3 and 4