Why is it essential to apply heat during the endospore staining process?

• A. Heat causes endospores to expand, making them more visible.
• B. Heat helps the primary stain, malachite green, penetrate the tough outer covering of endospores.
• C. Heat acts as a mordant to bind the counterstain to the cell wall.
• D. Heat prevents the decolorization of vegetative cells.

Answer: (B)