Indelible means permanent. An indelible moment would be something like going to a job interview and the first impression you make is indelible, it can't be changed or redone.
I think this means:
If it's possible for a human being to do something, don't just say that he can't, just let him try, give him a chance.
I am pretty sure that the correct answer on the question which is being asked is the first option from the scale. It helps you figure out what you already know and what you need to research about your topic. The word 'idea' in question helps you to understand that you don't need to take <span>extensive list of approaches or organizer of ideas as a basis.</span>
