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In the past, most children who went sledding in the winter snow in Verland used wooden sleds with runners and steering bars. Ten years ago, smooth plastic sleds became popular; they go faster than wooden sleds but are harder to steer and slow. The concern that plastic sleds are more dangerous is clearly borne out by the fact that the number of children injured while sledding was much higher last winter than it was 10 years ago.

Which of the following, if true in Verland, most seriously undermines the force of the evidence cited?

A. A few children still use the traditional wooden sleds.
B. Very few children wear any kind of protective gear, such as helmets, while sledding.
C. Plastic sleds can be used in a much variety of snow conditions than wooden sleds can.
D. Most sledding injuries occur when a sled collids with a tree, a rock, or another sled.
E. Because the traditional wooden sleds can carry more than one rider, an accident involving a wooden sled can result in several children being injured.

In the stimulus, I am a little bit confused. If plastic sleds are more dangerous, the number of children injured while sledding should be much lower last winter than it was 10 years ago. Because plastic sleds became popular in 10 years ago. Please correct me if I am wrong..