The symmetric difference of two sets A and B, denoted A Δ B, is defined as:
Answer: B
The symmetric difference of A and B is the set of elements which are in either of the sets, but not in their intersection.
This can be expressed in two common ways:
1. A Δ B = (A ∪ B) - (A ∩ B)
2. A Δ B = (A - B) ∪ (B - A)
Option B matches the first definition.