The relevant law is section 828(b)(2) of the civil code:
(2) If the proposed rent increase for that tenant is 10 percent or less of the rental amount charged to that tenant at any time during the 12 months prior to the effective date of the increase, either in and of itself or when combined with any other rent increases for the 12 months prior to the effective date of the increase, the notice shall be delivered at least 30 days prior to the effective date of the increase, and subject to Section 1013 of the Code of Civil Procedure if served by mail.
Your landlord is offering to renew your existing one-year lease for a 10% rent increase, and as such, a 40-day notice meets the requirements of "at least 30 days". The fact that you're also given the option to change your lease terms at an increase of more than 10% is irrelevant.