Which of the Following Sentences Provides a Reader with a Logical

Which of the following sentences provides a reader with a logical transition?

A) Every effort was made to find the source of the error, however, no conclusive evidence was found.
B) We searched high and low to find why the error occurred in the data that we collected and recorded in the field book notes that were done well.
C) The field notes were reviewed repeatedly to find the source of the error that was not found by those who were looking at the details.
D) None of the above