In Time Series Data, It Is Useful to Think of a Randomized

Multiple Choice

In time series data, it is useful to think of a randomized controlled experiment

A) consisting of the same subject being given different treatments at different points in time
B) consisting of different subjects being given the same treatment at the same point in time
C) as being non-existent (this is a time series after all, and there are no real "parallel universes"
D) consisting of the at least two subjects being given different treatments at the same point in time