Which statement correctly distinguishes true first-order from pseudo-first-order?

• A. True first-order depends on [A] and [B], pseudo-first-order depends only on [A]
• B. True first-order depends on [A] only; pseudo-first-order occurs when another reactant is effectively constant
• C. True first-order is when rate = k[A]^2, pseudo-first-order when rate = k'[A][B]
• D. True first-order occurs in a bimolecular step; pseudo-first-order occurs in a unimolecular step

Answer: (B)