Sentence Correction (SC) | Re: A potent Greenhouse gas

A potent green house gas , methane is formed in the environment from carbon dioxide and hydrogen , two major gases present in marshlands , are oxidized by bacteria

A) methane is formed in the environment from
B) methane is formed in the environment when
c) methane is formed in the environment and when
d) methane, formed in the environment from
e) methane, formed in the environment when