Ideally, a Patent Should Cover a Long Enough Period of Time

Ideally, a patent should cover a long enough period of time for the inventor to _______
, but that period should not be so long that it allows the inventor to _______.

A) earn a hearty return; charge a high monopoly price permanently
B) contribute to the social interest; only receive a slice of the social benefits
C) earn a rate of return; prevent broad public access to classic works
D) contribute to the social interest; prevent broad public access to inventions