If we measure a length $I=3.267 \mathrm{cm}$ with the help of a screw gauge, then which digits are absolutely correct and which is/are doubtful?

• A

  3,2 and 6 are absolutely correct and 7 is doubtful.

• B

  7,2 and 6 are absolutely correct and 3 is doubtful.

• C

  3,7 and 6 are absolutely correct and 2 is doubtful.

• D

  3,2 and 7 are absolutely correct and 6 is doubtful.