Please help I dont know which units it is exactly is it 3 or 4?

Answer:
B. 3 units
Seems correct by looking at it.
Sorry if i'm wrong
Step-by-step explanation:
Answer:
A'C' is still 3 units
Step-by-step explanation:
If we are just doing a rotation, the length of AC will not change
A'C' is still 3 units
A'B' is 4 units
B'C' = 6 units