Explanation : (C) The candle stops burning after sometime is an observation but the other two statements can't be observed. Thus, statement II and III are inferences.
Explanation : (D) Open-ended questions are the subjective type of questions which are answered with some creativity. They can also be called the free-response type of questions. The question "what would happen if force of friction ceased to exist?" has to be answered creatively while all other questions have some law behind them.
Explanation : (C) Law in science is the description of an observed phenomenon. It doesn't explain why the phenomenon exists or what causes it. The explanation of the phenomenon is called theory in science.