Answer:
Nucleus
the central and most important part of an object, movement, or group, forming the basis for its activity and growth.
Nucleolus
a small dense spherical structure in the nucleus of a cell during interphase.
The correct option is D.
Parietal cells are the epithelial cells which secrete hydrochloric acid and intrinsic factors. The cells are located in the gastric glands which are found in the linings of the walls of the stomach. The hydrochloric acid produced by the parietal cells helps in the conversion of the enzyme pepsinogen to pepsin during the digestion process.
Each of the term is identified whether they arise from the ectoderm, mesoderm or the endoderm.
The thyroid arises from the endoderm.
The thymus arises from the ectoderm.
The anterior pituitary arises from the ectoderm.
