What Does the Term "Continuum of Care" Mean in Terms

What does the term "continuum of care" mean in terms of working for a continuing care retirement community (CCRC) ?

A) A specific walking area within the inside of a nursing home to help measure distance.
B) A delivery of care over time as a person moves from being independent to needing assistance with personal and medical care.
C) A retirement community for all level of senior citizens that provides social activities as well as free meals and parties.
D) A nursing unit that provides basic care, medications, and physical therapy all on the same unit.