Which of the following are elements of a business that can develop a company's competitive...

Explanation

This is one of those questions you have to read carefully- it asks for 'elements of a business'. Cost focus and cost leadership are ways a company can improve their competitive advantage, but they're not elements of a business. The other three options are. Porter created a list of elements of a business that can help a company's competitive advantage- these can be found on p.33-34