Sonali took a toothpick and gently scraped the inner side of her cheek with it. she placed the contents of the toothpick on a clean glass slide containing a drop of water and then added a drop of methylene blue stain to it. She gently placed a cover slip over the slide and observed the glass slide under the microscope. The given illustration represents the observation made by sonali

The darkly stained region of cheek cells represents the

Options

A. nucleus
B. vacuole
C. cytoplasm
D. Mitochondria