I guess the answer is A,it may help you
The responses observed in type IV hypersensitivities result from the action of T cells and phagocytes.
Hypersensitivity IV type, also called delayed-type hypersensitivity (DTH), involves T cell-antigen interactions that cause activation and secretion of cytokines. This type of hypersensitivity requires sensitized lymphocytes that respond 24–48 hours after exposure to soluble antigens. A type IV hypersensitivity reaction is a cell-mediated reaction that can occur in response to contact with certain allergens, resulting in what is called contact dermatitis, or in response to certain diagnostic procedures such as the tuberculin skin test. Certain allergens need to be avoided to treat this condition. Type IV hypersensitivity response is observed results from the action of T cells and macrophages while other types are mediated by antibodies. This reaction occurs at least 1–3 days after the initial exposure. Type IV hypersensitivity is the mechanism of many autoimmune disorders.
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<span>What is the approximate age of our solar system?
</span>b. 4.6 billion years
The true statement about the arrangement of vascular bundles in monocot is:
B.) VASCULAR BUNDLES ARE SCATTERED IN THE GROUND TISSUE.
Characteristics of monocots are:
1) has one cotyledon
2) veins in leaves are usually parallel
3) flower parts are usually in multiples of three
4) arrangement of primary vascular bundles in the stem is scattered.
