Read each sentence to find out whether there is any grammatical error in it. The error, if any will be in one part of the sentence. The letter of that part is the answer. If there is no error, the answer is 'E'. (Ignore the errors of punctuation, if any).
The historian has been working on the project from last 12 years.
The historian
has been working
on the project
from last 12 years.
No error
Correct answer is D
for the last 12 years