Transfer pricing

The following are results for a division ;
Revenue 920
cost of sales 330
Gross profit 590

Other costs:
Attributable to divisional activities (70)
Attributable to the division (30)
Apportion head office costs (40)

Divisional profit 450

In a system of responsiblty accounting,for what amount of divisional profit should the divisional manager be held responsible??
A.590 B.520 C.490 D.450
Answer given is B…i know choices A&D are totally wrong.But what is wrong with C??isnt the divisional manager accountable for costs attributable to his division(30)??