Final answer:
The MTTU (Modular Test and Telemetry Unit) is the VAST system component responsible for synchronizing instructions between the computer and the system's functional blocks.
Step-by-step explanation:
The component of the VAST system that serves to synchronize instructions between the computer and the VAST system's functional building blocks is the MTTU (Modular Test and Telemetry Unit). The MTTU is responsible for coordinating the various tasks and ensuring that all components communicate effectively, enabling the system to perform diagnostics and automated testing.
The CPU (Central Processing Unit) handles the primary processing tasks of the computer, but the MTTU specifically is designed for task synchronization in VAST systems. Other options like the stimulus and measurement section and the DTU (Digital Telemetry Unit) play different roles, with the former providing signals and measurements for testing and the latter handling digital data telemetry.