5 on the test corrections

5. The primary sector includes all but which of the following?
A. manufacturing B. assembly
C. refining D. transportation construction
E. processing

i think that both a and d are not part of the primary sector. they are both in the secondary sector according to the book on pages 300 and 301. i know that there is a post by ms schencker about what to do about a right answer marked right, but i'm not sure what to do about this question. please help!
thanks