The correct answer is: A. Left
The ACP Guard shall proceed towards the front from the left side. This is because the ACP Guard is responsible for the safety of the President and other VIPs. If the ACP Guard were to proceed towards the front from the right side, they would be in a position where they could be easily attacked. By proceeding towards the front from the left side, the ACP Guard is able to protect the President and other VIPs from potential attackers.
Option B is incorrect because the ACP Guard is responsible for the safety of the President and other VIPs. If the ACP Guard were to proceed towards the front from the right side, they would be in a position where they could be easily attacked.
Option C is incorrect because the ACP Guard is responsible for the safety of the President and other VIPs. If the ACP Guard were to proceed towards the front from the back, they would be in a position where they could not protect the President and other VIPs from potential attackers.
Option D is incorrect because the ACP Guard is responsible for the safety of the President and other VIPs. The ACP Guard must proceed towards the front from the left side in order to protect the President and other VIPs from potential attackers.