What switch configuration will correct this problem?

The AP is unable to join the WLC. What switch configuration will correct this problem?

A.
interface vlanl
ip helper-address 10.10.10.10

B.
interface vlan20
ip helper-address 10.10.10.10

C.
ipdhcp pool vlanl
option 43 ascii ‘10.10.10.10’

D.
ip dhcp pool vlan20
option 43 ascii ‘10.10.10.10’

E.
ipdhcp pool vlanl
option 43 hex f1040a0a0a0a

F.
ip dhcp pool vlan20
option 43 hex f1040a0a0a0a