The correct answer to this question is B. A Gram stain, or Gram's method, is a technique for identifying two types of bacteria created by scientist Hans Christian Gram in 1884 in Berlin. First, a violet dye is applied, and then a decolorizing agent is applied.

Finally, a red dye is applied. The cell walls of the bacteria retain either the first blue dye (G+) or they retain the red dye (G-). This technique helps scientists quickly separate bacteria into two groups to quickly learn more about their cellular compositions. G+ bacteria have a thicker outer layer than G- bacteria.

The correct answer to this question is B. A Gram stain, or Gram's method, is a technique for identifying two types of bacteria created by scientist Hans Christian Gram in 1884 in Berlin. First, a violet dye is applied, and then a decolorizing agent is applied.

Finally, a red dye is applied. The cell walls of the bacteria retain either the first blue dye (G+) or they retain the red dye (G-). This technique helps scientists quickly separate bacteria into two groups to quickly learn more about their cellular compositions. G+ bacteria have a thicker outer layer than G- bacteria.