Final answer:
A Personal Digital Assistant (PDA) has the least processing power compared to server farms and supercomputers.
Step-by-step explanation:
Between the options listed, a Personal Digital Assistant (PDA) typically represents the type of computer with the least processing power. PDAs are considered basic compared to modern computing standards, offering limited computing capabilities. In contrast, Server Farms and Supercomputers possess a substantially higher processing power, being designed for heavy-duty computing tasks, with server farms consisting of numerous servers working together and supercomputers being at the pinnacle of processing capacity. Despite the mention of 'Server Farms' and 'Server Farm' as separate choices, they refer to the same category and are likely a typo; therefore, the answer focuses on the processing capabilities of PDAs compared to supercomputers and server farms.