Suppose the owners of a new bed and breakfast establishment are interested in conducting an experiment to determine effective advertisement strategies for increasing the number of reservations. The bed and breakfast owners intend to rotate advertisements for 12 weeks between a travel website, a travel magazine and a local billboard. Customers making reservations will be asked if they saw the advertisement. In this experiment, the independent variable is . a.
advertisement venue

b.
number of customer calls

c.
bed and breakfast establishment

d.
number of reservations

e.
travel website