When the concentration of A is doubled, the rate for the reaction: 2A + B → 2 C quadruples. When the concentration of B is doubled the rate remains the same. Which mechanism below is consistent with the experimental observations?a. Step 1: A + B ⇌ D (fast equilibrium) Step 2: A + D → 2 C (slow)b. Step 1: A + B → D (slow) Step 2: A + D ⇌ 2 C (fast equilibrium)c. Step 1: 2 A → D (slow) Step 2: B + D → E (fast) Step 3: E → 2 C (fast)d. Step 1: 2 A ⇌ D (fast equilibrium) Step 2: B + D → E (slow) Step 3: E → 2 C (fast)