If a rational expression has a common factor (x + 1) that cancels in simplification, must x = -1 be excluded from the simplified expression's domain?

• A. Only if (x + 1) also equals zero in the numerator at x = -1
• B. Yes — if original denominator was zero at x = -1, that value remains excluded even after cancellation of (x + 1)
• C. Only when working with rational numbers in decimals
• D. No — cancellation removes any previous restrictions so x = -1 is allowed after simplifying

Answer: (B)