I live in a rather large apartment complex. My landlord has suddenly decided to charge $40 a month for assigned parking.

I moved here from California where we had assigned parking (it is a state law in California that any apartment over 3- 4 apartments must provide assigned parking. When I moved here I was told here that they do not have assigned parking because it would be to dangerous because people would know that I was not at home. Now suddenly we were informed that we could have assigned parking for 40.00 a month. I do not want to pay that amount but suppose all of the spaces become "assigned?" Parking is already in my lease so if I opt out of paying an extra $40 and all of the spaces are assigned can the landlord do this although parking, not assigned parking is already in my lease? What are my options? I cannot park on the street because my apartment complex is on a highway with no parking.