Final answer:
Unlimited wants and limited resources are the factors that result in scarcity when they are both present, as the available supply is exceeded by human wants.
Step-by-step explanation:
The factors that result in scarcity when both are present are a) Unlimited wants and limited resources. Scarcity occurs because human wants for goods and services exceed the available supply due to limited resources. Even though demand is virtually unlimited, resources such as land, labor, and capital to produce goods and services are finite.
On the other hand, specialization refers to workers or firms focusing on tasks that they perform well within the production process. It is not directly associated with scarcity, but can affect the efficient use of resources. Similarly, the profit motive and entrepreneurship drive individuals and companies to innovate and create, which can have an impact on how resources are allocated, but these factors do not inherently result in scarcity. Lastly, innovation and a monopoly may lead to advancements and market dominance respectively, however, they are not direct causes of scarcity.