Final answer:
The most likely cause of a COP ignition system having no spark at any of the coils is excess resistance in the primary circuit.
Step-by-step explanation:
The most likely cause of a COP ignition system having no spark at any of the coils is excess resistance in the primary circuit. The primary circuit consists of the PCM (Powertrain Control Module), ignition coil, and the wiring/connectors between them. If the primary circuit has excess resistance, it can prevent the PCM from properly driving the ignition coil to create spark.
This excess resistance can be caused by a variety of factors such as corroded or loose connections, damaged wiring, or a faulty ignition coil. By inspecting and testing the primary circuit components and addressing any issues, you can restore spark to the coils.
It's important to note that while a faulty PCM driver (option A) or excess resistance in the secondary circuit (option C) can also cause a loss of spark, the most likely cause in this scenario is excess resistance in the primary circuit.