You Have a Job as a Summer Intern in an Orange

You have a job as a summer intern in an orange juice processing plant. Part of your job is to determine the amount of vitamin C in a given quantity of orange juice. To make this determination, you titrate the orange juice with I₃^-, the triiodide ion. To make sure you know what you are doing, your supervisor asks you how many electrons are transferred in the reaction. The reaction describing the titration is given below. What is your response? ascorbate + H₂O + I₃^- $\rightarrow$ dehydroascorbate + 2H⁺ + 3I^-

A) 1
B) 2
C) 4
D) 0
E) It is impossible to tell.