Odell and Kershaw run for 30 minutes on a circular track. Odell runs clockwise at 250 \mathrm{~m} / \mathrm{min} and uses the inner lane with a radius of 50 meters. Kershaw runs counterclockwise at 300 \mathrm{~m} / \mathrm{min} and uses the outer lane with a radius of 60 meters, starting on the same radial line as Odell. How many times after the start do they pass each other?
Answer Choices
A. 29
B. 42
C. 45
D. 47
E. 50