It was never taught at DD's school, and there is nothing in the CGP guide about independent companies testing drugs.
Page 7 of the AQA specification, "GCSE Biology for certification June 2014 onwards (version 1.1)"
"Evidence must be scrutinised for any potential bias of the experimenter, such as funding sources or allegiances."
Questions on exam papers, particularly those aimed at distinguishing the higher grades, won't just be recall of facts.