Answer is C. net income of the period
A is wrong because withdrawals by owners would only reduce the credit and not add anything to it.
B is also wrong since debiting the retained earnings will also decrease the equity so it will result in a net loss for the company.
Answer is C since crediting the net earning implies that the organization earned some profit which would increase the equity.
D is wrong too because the initial investment does not go to the retained earnings.
