My name was suggested by Davy on account of my colour i.e. greenish yellow. I have a pungent and suffocating odour. I am about 2.5 times heavier than air. I am soluble in water and also have a great affinity for hydrogen. WHO AM I?

Question

(a) Sulphur dioxide
(b) Ozone
(c) Oxygen
(d) Chlorine