In the following question, some part of the sentence may have errors. Find out which part of the sentence has an error and select the appropriate option. If a sentence is free from error, select 'No Error'.
Due to his negligence,(A)/ he failed (B)/ in the examination.(C)/ No Error (D)
Control processes depend on the prefrontal cortex which shrinks with age. Inadequate control processes may explain why many older adults have extensive vocabs (measured by written tests) but limited fluency (when they write or talk).