When baking soda is mixed with vinegar, which type of reaction has taken place?

            When baking soda is mixed with vinegar, a Neutralization reaction takes place.

Explanation:
                   The reaction of Baking sode (NaHCO₃) and Vinegar (Acetic Acid) takes place in two steps.

Step 1:
           In first step a Double Displacement Reaction takes place between baking soda and acetic acid.

               NaHCO₃  +  CH₃COOH    →    CH₃COONa  +  H₂CO₃

Step 2:
           The Carbonic acid (H₂CO₃) formed in first step undergoes Decomposition Reaction as it is unstable.

                                 H₂CO₃     →      CO₂    +    H₂O

Most likely a is the answer - because  you generate   38 atp's but also consume an atp.   each atp gives approx. less than 4 kcal so probably a is the closest answer.