Answer:
CD4 on the surface of helper T-cells.
Explanation:
MHC class II ( major histocompatibility complex) molecules are processed from the exogenous source. The presentation of antigen on cells are important for the adaptive immune response.
MHC class II interact with CD 4 present on the surface of T helper cells. This interaction is important for the generation of an immune response. Helper T cells can release cytokines and can perform phagocytosis.
Thus, the correct answer is option (C).
Your answer is A) - a greenhouse effect
that happens also at large scale, when the atmosphere is playing the role of the windows and the climate on earth became warmer.
A pollutant is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource.