A. Assets will increase by $40,000, liabilities will increase by $40,000, and stockholders' equity will remain unchanged
Cash is an asset account. As we receive cash when signing the promissory note, cash account increase therefore, assets increase by $40,000.
The note with the bank is a debt to the company. The comany assumes the obligation to pay it back. It creates a liablity for the company. Liabilities increase by $40,000.