Examine the following statements 1. Pneumatic systems are fire proof.2. Pneumatic systems are explosion proof.3. Hydraulic systems are explosion proof.4. Hydraulic systems are fire proof. Which of the above statements are correct?

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