Option 1: Dreser. This option is incorrect. There is no evidence to suggest that Dreser discovered sex hormones.
Option 2: Eugen Steinach. This is the correct option. Eugen Steinach, an Austrian physiologist, is credited with discovering sex hormones. He conducted extensive research on the endocrine system and published several papers on the topic.
Option 3: Edward Calvin. This option is incorrect. Edward Calvin, an American chemist, made important contributions to the field of organic chemistry but did not discover sex hormones.
Option 4: Samuel Cohen. This option is incorrect. Samuel Cohen is a common name and there is no specific information available regarding a Samuel Cohen discovering sex hormones.
To summarize, the correct answer is option 2, Eugen Steinach, who is credited with the discovery of sex hormones through his research on the endocrine system.