A man on a very urgent mission during a battle finds he must cross a stream about 40 feet wide. A blizzard has been blowing and the stream has frozen over. However, because of the snow, he does not know how thick the ice is. He sees two planks about 10 feet long near the point where he wishes to cross. He also knows where there is a bridge about 2 miles downstream. Under the circumstances he should:
A. Walk to the bridge and cross it.
B. Run rapidly across the ice.
C. Break the hole in the ice near the edge of the stream to see how deep stream is.
D. Cross with the aid of the planks, pushing one ahead of the other and walking on them.
E. Creep slowly across the ice.