The given expression simplifies to 0.

This means the correct answer is the third option: $\boxed{0}$.

Would you like further details on the simplification process or have any other questions?

Here are 5 related questions you might find helpful:

1. How do you simplify expressions involving fractions with different denominators?
2. What is the significance of factoring when simplifying algebraic expressions?
3. How does symmetry in terms like $a - b$ and $b - a$ affect simplification?
4. What techniques can be used to identify common factors in algebraic expressions?
5. How can you check if two complex expressions are equivalent?

Tip: Always check for possible factorizations in both the numerator and the denominator to simplify complex fractions more easily.