The retained earnings statement summarizes and explains changes in retained earnings during an accounting period. Which of the following is the correct sequence for the presentation of the statement of retained earnings at the end of a year ending on December $31,2021?$

a$.$ Retained Earnings, January $1,2021,+$ Net Income $-$ Dividends $=$ Retained Earnings, December $31,2021$

b$.$ Retained Earnings, January $1,2021,+$ Dividends $-$ Net Income $=$ Retained Earnings, December $31,2021$

c$.$ Retained Earnings, December $31,2021,+$ Net Income $+$ Dividends $=$ Retained Earnings, December $31,2021$

d$.$ Retained Earnings, December $31,2020,+$ Net Sales $-$ Dividends $=$ Retained Earnings, December $31,2021$