Which of the Following Features of a Systems-Thinking Approach Is

Which of the following features of a systems-thinking approach is best illustrated by this statement?
The combination of high levels of radon exposure and cigarette smoking has been found to multiply the incidence of lung cancer.

A) Systems-thinking focuses on the interconnections and interactions between health problems.
B) Systems-thinking looks for leverage points where specific actions can have a substantial impact.
C) Systems-thinking looks at how problems change over time.
D) Systems-thinking examines the impact of two or more simultaneous interventions.