The concept of the "security quandary" is based on providing a balancing act between what two elements?

Access and isolation are the two competing elements of the security quandary. A facility must allow legitimate entry and use (access) while simultaneously denying unauthorized entry (isolation), and every security design decision is a trade-off between these two opposing requirements.

Risk and threat are related analytical concepts used to assess the security environment, but they are not the two opposing operational elements that define the security quandary balancing act.

Asset and isolation are not opposing forces in the quandary - an asset is what is being protected, not a variable that is balanced against isolation in system design.

Asset and risk describe what you are protecting and the probability of loss, but they are assessment inputs, not the two competing design pressures that constitute the security quandary.

Access and cost involve a financial consideration that is a project management constraint, not the fundamental security design tension that defines the security quandary concept.