ohn recently suffered a blow to the head. Since then, he has found it quite difficult to express his thoughts. Although his ability to think has not been impaired, he cannot find the right words to say what he wants to say. However, he speaks freely and with proper syntax. John most likely suffers from _____.
a. retrograde amnesia
b. Broca's aphasia
c. Wernicke's aphasia
d. Epilepsy