Which of the following answers below is the correctly balanced half-reaction for the reduction of the SO4 ^-2 ion in acid solution? The answer is C, but I don’t understand why. Thanks in advance :-)

Calculate: select the worksheet tab. this tab you calculate the analyte concentration.  fill in the first set of boxes ("moles h2so4" and "moles naoh") based on the coefficients in the balanced equation. (if there is no coefficient, the value is 1.)  record the appropriate volumes in the "ml naoh" and "ml h2so4" boxes.  record the concentration of the titrant in the m naoh box. click calculate. what is the concentration listed