Following is the stockholders' equity section of the Merck \& Co., Inc., balance sheet. a. Explain the derivation of the \$1,657 million in the common stock account. Complete the calculation of total amount of shares. Enter share amounts in millions ($3,000,000=$3). Round share amounts to the nearest whole number. * million shares X$ = million b. Using December 31, current year balances, at what average issue price were the Merck common shares issued? Round answer to two decimal places. $ c. At what average cost was the Merck treasury stock as of December 31 of the current year? Round answer to two decimal places. $ d. How many common shares are outstanding as of December 31 of the current year? Enter full number - do not convert to millions or round answer. shares