Request on an option

How does the person interested in buying the option know about your book, and what it's about?

As options are often sold for very little it's not necessarily a big plus point, but if the person who has expressed an interest is of some repute, it couldn't hurt to mention this in your query.

It could be an incentive to an agent if the animation company is well known and could get a publisher therefore more interested in the book. But the thing I'd also advise is it might be worth waiting until you have the agent. I've had my agent deal with several options, and there are certain things that some development companies won't offer you that are considered pretty standard for option contracts. Agents can help make sure you get everything you need to protect you, and the money you deserve for your work (not so much with the option itself, as Old Hack said the money for an option isn't that much usually, but subsequent monies CAN be).