It depends on your contract and the seller. I would think that a lease option wouldn't be as attractive to most sellers as a conventional sale. Consider dropping the price or upping the marketing on your home to improve your chance of selling. This will give the seller's reason to wait for you in case they are tempted by the lease option.
I take it your represented by a real estate agent on the sale of your home. I would suggest you consult your agent on this issue or a real estate attorney. I would love to help you but this is an issue between your agent or an attorney. Good luck to you and if I can help with anything else feel free to contact me direct.
Century 21 First Realty Appleton