Adobe Acrobat reader is free. Adobe does this to build a market for the sale of software that creates Acrobat files. This is an example of: (pick all that apply)
a. firms taking advantage of complementary products developed for a prior generation of technology.
b. firms giving away products for half of a two-sided market.
c. firms spreading costs across increasing units of production or in serving multiple customers.
d. seeding the market. on market attempting to conquer a new market by making it a subset, component, or feature of its primary offering.