Final answer:
Issuing stock for cash is the financing activity among the options given as it involves raising capital by selling ownership stakes in the company to the public.
Step-by-step explanation:
The activity that is considered a financing activity of a business among the options provided is Issuing stock for cash . Financing activities involve transactions designed to fund a company, including debt, equity, and dividends. When a company issuse stock, it is selling ownership in the company to the public to raise capital, in contrast with operations like purchasing a plant or paying for inventory which are investing and operating activities respectively. Paying salaries is also considered an operating activity as it relates to the daily operations of the business.