Rainbow airlines has experienced a continuing and unexplained decline in the number of tickets sold on its major routes from new york to san francisco. you have been asked to give the senior vice-president of the marketing division a report on the problem and to outline alternative courses of action for the airline to take. how would you start?
a. descriptive research
b. a survey of rainbow airlines' passengers
c. a survey of passengers who patronize competing airlines
d. exploratory research
e. causal research