Discuss the feasibility of each type of survey mode for each of the following cases:
a. Fabergé wants to test a new fragrance called "Lime Brut."
b. Kelly Services needs to determine how many businesses expect to hire temporary secretaries for those who go on vacation in the summer.
c. The Britannica Online for Kids requires information on the degree to which parents of elementary school-aged children see encyclopedias as worthwhile purchases for their children.
d. AT&T is considering a television screen phone system and wants to know people's reaction to it.