Three commonly utilized methods for determining product$/$service demand are

A$.$ talking face$-$to$-$face with potential customers; utilizing online tools, such as Google AdWords and landing pages; and library, Internet and gumshoe research

B$.$ assessing target market attractiveness; utilizing online tools, such as Google AdWords and landing pages; and calculating total startup cash needed

C$.$ analyzing the financial performance of other businesses, talking face$-$to$-$face with potential customers, and assessing target market attractiveness

D$.$ assessing the overall financial attractiveness of the proposed venture, talking face$-$to$-$face with potential customers, and assessing industry attractiveness