In the following pairs of the words that share the same root, which pair is marked correctly on the primary stress?

In the following pairs of the words that share the same root, which pair is marked correctly on the primary stress?
A.'photo, photo'grapher
B.'celebrate, cele'brity
C.de'mocracy,　demo'cratic
D.po'litical, 'politician
正确答案：de'mocracy,　demo'cratic