Most tumors that originate in the brain are not cancer, but growth of any tumor within the confined space of the skull can put pressure on surrounding nervous tissue and thus harm neurons. Treating brain tumors with drugs is difficult because of the blood–brain barrier. Lipid-soluble drugs can penetrate this barrier, but they get into and affect all other cells too. Explain why.

(A). epithelial tissue.

Explanation:

Angiogenesis inhibitors can be defined as anti-cancer drugs that inhibit growth and development of newly formed blood vessels around tumors.

These drugs are used in cancer treatment of various types of cancer. This is because, most of the cells receive nutrients and oxygen from blood supply and these drugs cut off the blood supply to tumorous cells.

However, angiogenesis inhibitors would be least effective for treatment of tumors in epithelial tissue as epithelial tissues do to not have blood vessels. These tissue receive nutrients and oxygen from tissue present beneath the epithelial cells.

Thus, the correct answer is option (A).