Answer:
The treatment offered to the people in the local nursing home which is - Serving them herbal tea and talking with them.
Step-by-step explanation:
An explanatory variable is a kind of independent variable whose level of independence is not definite. Explanatory variables give us an insight into the reason for the problem which we seek to resolve through the experiment. In the given question we are trying to determine the possibility that herbal tea has remarkable restorative powers. This is the focus of the experiment or response variable.
The explanatory variable then provides an explanation that would help us evaluate the degree of accuracy of this hypothesis. This is seen in the form of weekly visits to a local nursing home, visiting with residents, talking with them and serving them herbal tea. The aforementioned are the treatment administered to the participants in the experiment to provide some sort of explanation to the hypothesis.