Stain used for staining the nucleus is?

Ans. is 'c' i.e., Hematoxylin * Hematoxylin and eosin staining is used frequently in histology to examine thin sections of tissue. Hematoxylin stains the cell nucleus and other acidic structures (such as RNA-rich portions of the cytoplasm and the matrix of hyaline cartilage) blue, while eosin stains cytoplasm, connective tissue and other extracellular substances pink or red.* Eosin is strongly absorbed by red blood cells, coloring them bright red. In a H & E preparation the red blood cells are almost orange, and collagen and cytoplasm (especially muscle) acquire different shades of pink.