Legal Question in Business Law in California

Most likely not. If the renewal is for more than a year, there is authority that it must be in writing, just as an original lease for more than a year must be in writing.

See California's Statute of Frauds, Civil Code section 1624, especially subsection (a)(3).

In theory, yes. See Ripani v. Liberty Loan Corp. (1979) 95 Cal.App.3d 603. However, almost all leases have a separate provision that explains how any notice under the lease is to be provided. This provision usually requires written notice, and gives a contact address. In addition, this provision also covers how notice is to be given for the exercise of the option.

A landlord can waive the specifics of the notice provision and accept an oral exercise of an option, if he so chooses. If your landlord is being difficult, I would purchase a half-hour of a lawyer's time to review the lease and discuss the facts in your situation.