Final answer:
The assets must equal liabilities plus stockholders equity, because stockholders equity is the difference between the assets and the liabilities.
Step-by-step explanation:
The left and right sides of a balance sheet are equal because assets must equal liabilities plus stockholders' equity. Stockholders' equity represents the difference between assets and liabilities. In other words, it is the residual claim of the owners of the business after deducting liabilities from assets.
For example, if a company has $100,000 in assets and $50,000 in liabilities, the stockholders' equity would be $50,000 ($100,000 - $50,000 = $50,000).
Therefore, option a. "The assets must equal liabilities plus stockholders equity, because stockholders equity is the difference between the assets and the liabilities" best describes why the left and right sides of a balance sheet are equal.