I choice letter d. Friendship may first develop from sharing interests and having adventures, but profound relationship are built on trust, honesty, and support. Because every relationship start from friends to higher relationship like best friends but before that you need to know your people around you. So you need to know them by trusting them and to be honest to others to avoid misunderstanding to them. HONESTY is the best policy in terms of any kind of relationship then followed by SUPPORT. Everyone will support your plan or decision making specially it tackles about your personal lives.They will help you no matter what happen because best friends long last or their is forever in friendships.
Polonius is using his daughter to spy her conversation with Hamlet. He teaches how to act naturally, how to walk and pretend that she is reading.
In that last phrase, he is saying that we humans often act in deceitful ways, for which we are to blame.
He admits that he is making a mistake, in teaching that kind of behaviour to his own daughter.
If it had to be the same answer the beginning because you don't introduce characters in the middle or end!!!
If it can be different then conflict would be middle and characters would be begging because a conflict is most likely to be in the middle: the most action packed part of the book.