The most important part of preparing a presentation aid is to
a. practice using the aid
b. keep the aid a secret
c. make the aid as elaborate as possible.
d. request the of as many people as necessary

The most important part of preparing a presentation aid is to "practice using the aid".

The accompanying rules are helpful while preparing presentation aids:
• Make drafts of aids at that point utilize them amid a practice. Consider requesting that somebody see the practice and influence recommendations as to the propriety of the guides and any changes that could be made. Instantly make note of upgrades to be made as they are recognized. 
• Rehearse with back-up aids also. An introduction utilizing electronic media may run easily however utilizing flip graphs for a similar material might be a little unbalanced at first. 
• Don't make aids at the last moment. Ineffectively created and thoroughly considered aids will influence a moderator to look not well arranged and can destroy a decent introduction.

You have to write your reactions like what you agree and disagree with