The reaction: 2A + 2B --> D + F was studied carefully and the following mechanism was finally Determined to be the following: A+ A--> C (slow) C+B --> D+E (fast) E + B --> (very fast) The rate law for the reaction would therefore be 1) rate = K[A] 2) rate = K[A][B] 3) rate = K[C][B] 4) rate= K[A][B]3 (5) rate = K[A][B]