How to make DSW1 the primary root for VLAN 10?

Refer to the exhibit.

How to make DSW1 the primary root for VLAN 10? (Choose two)
A . DWS1(config-if)#spanning-tree port-priority 0
B . DSW2(config-if)#spanning-tree port-priority 16
C . DSW1(config-if)#interface gi1/3
D . DSW2(config-if)#interface gi1/3
E . DSW2(config-if)#spanning-tree port-priority 128

View Answer

Answer: A C (?)