What condition is characterized by hydrocephalus?

Hydrocephalus is a medical condition where there is an abnormal accumulation of cerebrospinal fluid (CSF) within the ventricles of the brain. This buildup can lead to increased intracranial pressure, which may affect brain function and development. The ventricles are fluid-filled spaces in the brain that contain CSF, which serves to cushion and protect the brain, as well as circulate nutrients. In hydrocephalus, either the production of CSF is too high, its absorption is too low, or there is an obstruction preventing its normal flow.

The reasons why the other options do not correctly describe hydrocephalus include: excess fluid in the lungs pertains to pulmonary edema, a condition associated with the respiratory system; a buildup of fluid in the abdomen refers to ascites, which is related to conditions affecting the liver or heart; and a reduction in cerebrospinal fluid production does not accurately describe hydrocephalus, as this condition specifically involves an excess of CSF rather than a deficiency. Thus, the identification of hydrocephalus as the abnormal condition where cerebrospinal fluid collects in the brain's ventricles makes choice B the correct answer.