Cheri North Has a Month-To-Month Tenancy

Cheri North has a month-to-month tenancy. She pays her rent of $880 on the first day of each month. On January 15, 2021, Cheri received notice from her landlord that her rent would be increasing to $900 per month. When is the first time the landlord can demand the $900 rent from Cheri?

A) The landlord can collect the extra $20 on January 15, 2021 and receive $900 on February 1^st and thereafter
B) The landlord can collect the $900 on February 1^st and every month after
C) The landlord can collect the $900 beginning March 1, 2021
D) The landlord will need to switch to a tenancy for years to implement the rate increase