Many Researchers Devise "Sham" Treatments for Their Control Groups to Undergo

Multiple Choice

Many researchers devise "sham" treatments for their control groups to undergo, meaning that the control group interacts with researchers in some way that is not thought to impact the dependent variable, or the outcome. This is done to weaken the argument that the treatment group improvement may have occurred in part simply due to the attention this group received from the researchers. These researchers are attempting to control for which of the following?

A) multiple treatment interference
B) the Hawthorne effect
C) selection
D) experimenter effects