Answer: Option D.
Explanation: The question states that there's a tornado WARNING in the area. This means John needs to take cover immediately. Staying on the road can be dangerous for both John and other drivers. Chasing the tornado is just stupid. Going to the top of a bridge is incredibly dangerous as he can easily get knocked off by strong wind and debris. John's best bet is to find a low flat area so the storm can do the least amount of danage to him and hopefully debris will fly over him.