If a disease has an unknown cause, then it is said to be

a. teratogenic.
b. idiopathic.
c. venereal.
d. fulminating.

Correct B). Idiopathic

An idiopathic disease is any disease or disorder, which is caused due to an unknown cause or mechanism. When the doctor is not sure about the cause of disease, then such type of disease is called idiopathic disease. It is a Greek word, in which idios means own and pathos means suffering. It means a disease of its own kind.

Example: Acute idiopathic polyneuritis, idiopathic pulmonary fibrosis etc.

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.