In LC-MS, the interface connects the liquid chromatography (LC) system with the mass spectrometer (MS). The liquid chromatography separates the sample components, and the mass spectrometer detects them based on their mass-to-charge ratio. The interface between LC and MS is crucial for transferring the eluted compounds from the chromatographic column to the mass spectrometer for analysis.
Thus, the correct answer is (b) Liquid chromatography and mass spectrometer.