What Is One Difference Between a Time-Series Design and an Interrupted

Multiple Choice

What is one difference between a time-series design and an interrupted time-series design?

A) Time series examines the effect of a treatment and interrupted time series examines the effect of an outside event.
B) Time series examines the effect of an outside event and interrupted time series examines the effect of a treatment.
C) Time series involves several observations before and after the treatment/event and interrupted time series has only one observation before and after.
D) Time series involves only one observation before and after the treatment/event and interrupted time series has several observations before and after.