What is the most likely system acquisition methodcommencial software, custom software, or ERP$-$for each of the following situations? Explain your answers.

A heating and air$-$conditioning supply company with $20$ employees that sells standard off$-$the$-$shelf products to wholesale customers in a local community needs a system to manage its affairs.

A major oil company with diverse holdings, complex oil leases, and esoteric accounting practices needs a system that can coordinate its many enterprises.

A large organization with multiple divisions needs an information system to support its operations. The information needs of the various divisions are diverse but standard within their respective industries.