One of T Companys cost pools is parts administration. The expected overhead cost for that cost pool was $380,000 and the expected activity was 5,000 part types. The actual overhead cost for the cost pool was $420,000 at an actual activity of 6,000 part types. The activity rate for that cost pool was: a) $63 per part type b) $76 per part type c) $70 per part type d) $84 per part type