It is by far the most widely used method for determining the number of viable cells in a food product–

Correct option is D

Option (a): Incorrect
• MPN (Most Probable Number) is used for estimating microbial load in liquids, especially coliforms, but it is not the most widely used method overall.
Option (b): Incorrect
• DEFT (Direct Epifluorescent Filter Technique) is rapid but used for specific applications, not general viable count determination.
Option (c): Incorrect
• DMC (Direct Microscopic Count) counts both live and dead cells; it cannot determine viable cells, so it is not a preferred method.
Option (d): Correct
• SPC (Standard Plate Count) is the most widely used method to determine number of viable microorganisms in food.
• It measures only live cells capable of forming colonies and is the standard reference method in food microbiology.