Final answer:
Ramona's failure to recognize that a coin could be used to turn a screw is a demonstration of functional fixedness, a cognitive bias where individuals are unable to use objects in novel ways due to familiarity with their common functions.
Step-by-step explanation:
Ramona's oversight best illustrates a common cognitive bias known as functional fixedness. This term refers to a mental block against using an object in a new way that is required to solve a problem. It involves the inability to see a new use for an object because the person is so familiar with its common use.
This oversight is not just about lacking the physical tool, like a screwdriver, but about the failure to recognize an alternative method (using a coin) that could achieve the same goal. Functional fixedness is a tendency to only see the conventional function of objects, disregarding their potential use in different, unconventional ways.