Step 1 : Introduction to the question "6. The gas attack on the Tokyo Subway killed relatively few but injured many. What type of gas was used?"
...1. Lewisite 2. Soman 3. Tabun 4. Sarin Aum Shinrikyo, religious terrorists from Japan, were the responsible for the subway attack. Five men entered the subway at different points, releasing the chemical. Twelve people were killed, 50 were seriously injured and a further 984 suffered temporary poisoning.