How are the slot groups arranged in the ERX 700 Series Edge Router?

A.
Group 1 – Slots 0 &1
Group 2 – Slot 2
Group 3 – Slot 3
Group 4 – Slot 4

B.
Group 1 – Slots 2 & 3
Group 2 – Slot 4
Group 3 – Slot 5
Group 4 – Slot 6

C.
Group 1 – Slot 2
Group 2 – Slot 3
Group 3 – Slot 4
Group 4 – Slot 5 & 6