Final answer:
The middle cerebral artery is the key artery for acquired language disorder. It supplies blood to the brain areas responsible for language processing and comprehension, and when affected, can result in difficulties with speaking, understanding, reading, or writing.
Step-by-step explanation:
The correct answer is a. Middle cerebral artery. The middle cerebral artery is a major artery of the brain that supplies blood to the lateral aspects of the cerebral hemispheres, including the temporal and parietal lobes. It is responsible for providing blood to areas of the brain that are involved in language processing and comprehension.
When this artery is affected, it can result in acquired language disorder, also known as aphasia which is a condition characterized by difficulty speaking, understanding, reading or writing.