You want to enable IS-IS on your Junos device, with ge-0/0/1 as a Level 2 only interface.
Which commands are necessary?

A.
set interfaces lo0 unit 0 family iso address 49.0001.0921.0168.0201.00
set interfaces ge-0/0/1 unit 0 family iso
set protocols isis interface ge-0/0/1 level 1 disable

B.
set protocols isis interface ge-0/0/1 enable
set interfaces lo0 unit 0 family iso address 49.0001.0921.0168.0201.00
set interfaces ge-0/0/1 unit 0 family iso level 1 disable

C.
set interfaces lo0 unit 0 family iso address 49.0001.0921.0168.0201.00
set interfaces ge-0/0/1 unit 0 family iso level 2

D.
set protocols isis interface ge-0/0/1 enable
set interfaces lo0 unit 0 family iso address 49.0001.0921.0168.0201.00

set interfaces ge-0/0/1 unit 0 family iso level 2