What routine maintenance is essential for FDM printers?

Routine maintenance is crucial for ensuring the optimal performance and longevity of Fused Deposition Modeling (FDM) printers. Regularly cleaning the nozzle helps prevent clogs and ensures a consistent flow of filament, which is vital for a quality print. Additionally, checking the bed alignment ensures that the print surface is level, which is critical for the first layer's adhesion and overall print quality. Maintaining these aspects enhances reliability and efficiency in the printing process, thus making option B the best answer.

Other options, while they may mention relevant practices, do not reflect the practical and necessary routine maintenance required for FDM printers. For instance, replacing the entire printer yearly is neither cost-effective nor practical, as proper maintenance can extend the lifespan of the printer significantly. Updating slicing software weekly isn't generally required; updates should be performed to improve functionality but not at such a frequent interval unless specific issues arise. Lastly, calibrating only after every ten prints could lead to inconsistencies in print quality, as regular calibration, based on usage, is essential for optimal performance.