On January 1, 2020, a company had in its equity the account of "Accumulated Other Comprehensive Income" (AOCI) with debit balance (Loss). On December 31, 2020, the account balance was credit. What could be the cause(s) for this change?

a. A portion of the loss in AOCI was reclassified to the Statement of Income and Expenses.

b. The company had during 2020 a significant amount of unrealized earnings that were recognized as Other Comprehensive Income.

c. Both a and b represent possible causes.

d. Neither a nor b are possible causes.