Final answer:
The correct option is c. The Gram stain, acid-fast stain, and endospore stain are all differential staining techniques used to identify specific types of microorganisms, and they involve multiple steps. However, they were not developed by Louis Pasteur.
Step-by-step explanation:
The Gram stain, acid-fast stain, and endospore stain have the following in common: c) They were developed by Louis Pasteur The Gram stain, acid-fast stain, and endospore stain are all differential staining techniques used to identify specific types of microorganisms. However, they were not developed by Louis Pasteur.
The Gram stain was developed by Hans Christian Gram, the acid-fast stain was developed by Ziehl-Neelsen and the Kinyoun techniques, and the endospore stain was developed by several different scientists over time. The staining techniques involve multiple steps and are used to differentiate between different types of microorganisms based on their physical and chemical properties.