What is used to align the hydraulic system?

The correct choice is EOSS, which stands for Engineering Operational Sequencing System. This system is utilized to ensure that the various components of a hydraulic system are aligned and functioning in a coordinated manner. EOSS provides guidance on the operational procedures and sequences necessary to correctly operate hydraulic systems, thereby ensuring efficiency and safety in their use.

In a hydraulic system, proper alignment is critical to prevent operational failures and ensure optimal performance. EOSS includes specific instructions for starting, running, and shutting down the system, which helps in maintaining the alignment of the hydraulic components throughout their operation.