OGOO Rising with AGO, page-13

When you buy an option you reserve the right to buy a share at a certain date at a certain price. In this case the strike price is 7.5c which means the date the options expire you can buy a share at 7.5c equal to the amount of options you own even if they are trading at 8c, 12c, or $1. You can only do this on a specific date (expiry date) which is around June I think.
The risk is if the trading price is 6c on the expiry your options are worthless because why would you pay 7.5c for a share that is trading for 6c?
Im still a bit new at this, but thats how I understand them, did i miss anything?