My choice is D.
While TPUs offer faster training, they can be less convenient for debugging due to limitations in tooling and visualization, such as the lack of support for some debuggers and limited visualization options.
Comparing options C and D, MultiWorkerMirroredStrategy uses synchronous distributed training across multiple workers, making it easier to inspect intermediate states and variables during debugging. In contrast, ParameterServerStraregv utilizes asynchronous multi-machine training, which can be less intuitive to debug. However, it's important to note that ParameterServerStraregv might be more efficient for training extremely large models. Therefore, considering the specific need for ease of debugging in this scenario, MultiWorkerMirroredStrategy appears to be the more suitable choice.