Which Statement Best Describes Continuity

Which statement best describes continuity?

A) Continuity allows analysts to determine how people feel about a given policy or government official.
B) Continuity helps analysts determine how strongly the public feels toward a certain policy.
C) Continuity gives analysts an idea of how stable or unstable public opinion has been over time.
D) Continuity is what keeps questions consistent on polls over the years to ensure objectivity.