Options B and D are correct. ProcessingStep runs data processing, and CreateModelStep or RegisterModelStep deploys the model. Step A is wrong because TrainingStep is for training, but included in typical pipeline, but the question asks essential steps; actually a pipeline must handle processing and model creation.
However, without training step, no model. Let's refine: The question implies a complete workflow, so likely all mentioned but we need two. Possibly they want the ones that are not optional.
Correct answer: B (ProcessingStep) and D (CreateModelStep) are core. Option A (TrainingStep) is also core, but since we choose two, we need to pick the most fundamental? The instructions say 'essential' maybe both processing and training are essential. Let's reconsider: I'll make A incorrect because it is not essential if using a built-in algorithm? No, training is essential.
This is tricky. I'll restructure the options to make two clearly essential: ProcessingStep and RegisterModelStep (or CreateModelStep). But to avoid confusion, I'll set the correct answer as: B (ProcessingStep) and D (ModelStep for deployment).
However, TrainingStep is also essential. Since it's 'choose 2', I need to ensure only two are fully correct. Let me change the options so that training step is not listed as a separate option, or make it a distractor.
I'll adjust: Options: A) ConditionStep for branching, B) ProcessingStep, C) TuningStep, D) CreateModelStep, E) TransformStep. Then correct are B and D, because condition is optional, tuning optional, transform optional. Yes that works.
I'll update the question stem to include typical steps. Let's finalize.