Please choose the correct answer to the question: Which is true of scientific discoveries?

Answer1: All scientific discoveries are based solely on observation and never experimentation. Answer2: Sometimes scientific discoveries are made by accident, like the discovery of penicillin. Answer3: If a scientist cannot provide the exact time and place his or her discovery was made, it is dismissed. Answer4: All scientific discoveries are regulated by government agencies, like the Food and Drug Administration.

Answer format: answer1/answer2/answer3/answer4
Answer: answer2