In the Context of a Controlled Experiment,consider the Simple Linear

Multiple Choice

In the context of a controlled experiment,consider the simple linear regression formulation Yi = β0 + β1Xi + ui.Let the Yi be the outcome,Xi the treatment level when the treatment is binary,and ui contain all the additional determinants of the outcome.Then calling a differences estimator

A) makes sense since it is the difference between the sample average outcome of the treatment group and the sample average outcome of the control group.
B) and the level estimator is standard terminology in randomized controlled experiments.
C) does not make sense,since neither Y nor X are in differences.
D) is not quite accurate since it is actually the derivative of Y on X.