Which of the following citations is a legally proper citation of other people's work within the scope of reason? (1)To write an investment report on the drug trade. (2)Screengrabs of any comments or posts online can be appended to research reports without especially indicating the source. (3)Teachers using other people's works in class for teaching purposes and cites the source. (4)Researchers copying entire books themselves risk violating copyright laws, but asking photocopy shops to copy books is not illegal