Write the next sentence in this paragraph:

How to sell or swap gift cards
Use a gift card market site.
There are sites online that allow you to swap and sell gift cards, known as gift card marketplaces. These sites offer a balance guarantee on any card purchased or sold through them.

Select from:
[a]. To determine the balance you need, go online and take a look. However, you will need to be sure the card is legitimate or else it could be counterfeit.;
[b]. This ensures you are not scammed or given an unfair price for the gift card. They work as the middleman between buyers and sellers so you only deal with the company and not with any third parties.;
[c]. Fannie mae's pinterest usa is a great resource for online trading under the umbrella of pinterest. You can only trade gifts from reputable sites based on a verified email or phone number.;
[d]. Most of these sites also allow you to trade using cash, a credit card, and a paid debit card. When exchanging cards, you sign in with a credit card, or sign up with a debit card.;
[b].