You can see other respondent's response also after answering this survey.
https://docs.google.com/forms/d/1IQUo4ENuTTP2TCTlQH2G_2QXkVtOyE8VyVr_dJgzGcc/viewform?usp=send_form
<iframe src="https://docs.google.com/forms/d/1IQUo4ENuTTP2TCTlQH2G_2QXkVtOyE8VyVr_dJgzGcc/viewform?embedded=true" width="760" height="500" frameborder="0" marginheight="0" marginwidth="0">Loading...</iframe>
Since I am a Chemistry teacher, I have a biased opinon. I always say that Chemistry is the easiest topic in O Level. This survey started in May 21 / 2014. We'll see the result next year.