Which of the following most accurately describes the relationship between air pollution and lung cancer?

Which of the following most accurately describes the relationship between air pollution and lung cancer?

a. Fine particles yield the highest risk of lung cancer because they can penetrate further into the lungs.
b. A 1% increase in the concentration of particles in the air corresponds to a 2.5 times higher risk of developing lung cancer.
c. Fine particles greater than the diameter of a single human hair penetrate farthest into the lungs.
d. Particles <100 nanometers in diameter yield the highest risk of lung cancer
e. Asbestos fibers are a very a common air pollutant known to cause mesothelioma (a malignancy of the pleura surrounding the lung)