Technician A says that an ECU/PCM is needed to make EFI systems function correctly. Technician B says that most early EFI systems were throttle body injection type systems. Who is correct? a. Technician A b. Technician B c. Both Technician A and Technician B d. Neither Technician A nor Technician B

c. Both Technician A and Technician B<br /><br />Explanation:<br />- Technician A is correct in stating that an Electronic Control Unit (ECU) or Powertrain Control Module (PCM) is necessary for the proper functioning of Electronic Fuel Injection (EFI) systems. The ECU/PCM manages various engine functions and ensures optimal performance and efficiency.<br />- Technician B is also correct in noting that most early EFI systems were throttle body injection (TBI) type systems. In TBI systems, the fuel is injected into the throttle body, which is located on top of the engine's intake manifold. This was a common setup in early EFI systems before the development of more advanced systems like multi-port fuel injection.