If a transaction affected two accounts and total liabilities decreased by $$4,000,$ then

total assets must have decreased by $$4,000.$

total stockholders' equity must have decreased by $$4,000.$

total assets must have decreased by $$4,000$ or total stockholders' equity must have increased by $$4,000.$

total assets and total stockholders' equity each must have increased by $$2,000.$

total assets must have increased by $$4,000$ or stockholders' equity must have decreased by $$4,000.$