【正确答案】 B

【答案解析】Choice A: Buying fixed assets on credit does not affect current assets but increases current liabilities. Therefore, the current ratio falls. Choice B: Buying inventory on account increases both inventory and accounts payable. Because the current ratio started off below 1, the ratio will increase. Choice C: Selling marketable securities for cash does not affect the amount of current assets and leaves the current ratio unaffected.