Solution
✅ Correct Option: 3
Shiftless means lazy and unwilling to work. The word "idle" just before also suggests the same or someone who has nothing to do. Hence, Option 3 is the answer.
Amiable - Means to have a pleasant and friendly manner.
Ruthless - Means to be savage and brutal.
Carefree - Means to have nothing to worry about. There is a difference between "having nothing to do" and "not willing to do anything," hence it doesn't fit to be the answer.