Final answer:
Mass spectrometry involves generating gas phase ions from intact microorganisms to obtain a mass spectrum for identification.
Step-by-step explanation:
The method that involves the generation of gas phase ions from intact microorganisms is b) Mass spectrometry. Mass spectrometry is a technique used to analyze the chemical composition of a sample, including microorganisms. In the case of microorganisms, the technique involves generating gas phase ions from the various chemical constituents of the microorganism, which are then collected and analyzed to obtain a mass spectrum for the organism. This mass spectrum can be compared to a database of known microorganisms for identification.