Price controls are usually enacted
a. as a means of raising revenue for public purposes.
b. when policymakers believe that the market price of a good or service is unfair to buyers or sellers.
c. when policymakers tax a good.
d. all of the above are correct.

Option (B)

Explanation:

Price controls are described as the restrictions which is set in the place and thus enforced by the federal governments, these are set up on prices which are charged for the commodities, goods and the services in the market. The sloe intent that lies behind enforcing such authority can born from desire in order to maintain the affordability of these commodity especially during the shortages, and also in order to slow the inflation.

the earth’s crust is broken into separate pieces called tectonic plates (fig. 7.14). recall that the crust is the solid, rocky, outer shell of the planet. it is composed of two distinctly different types of material: the less-dense continental crust and the more-dense oceanic crust. both types of crust rest atop solid, upper mantle material. the upper mantle, in turn, floats on a denser layer of lower mantle that is much like thick molten tar.

each tectonic plate is free-floating and can move independently. earthquakes and volcanoes are the direct result of the movement of tectonic plates at fault lines. the term fault is used to describe the boundary between tectonic plates. most of the earthquakes and volcanoes around the pacific ocean basin—a pattern known as the “ring of fire”—are due to the movement of tectonic plates in this region. other observable results of short-term plate movement include the gradual widening of the great rift lakes in eastern africa and the rising of the himalayan mountain range. the motion of plates can be described in four general patterns:

collision: when two continental plates are shoved together

subduction: when one plate plunges beneath another (fig. 7.15)

spreading: when two plates are pushed apart (fig. 7.15)

transform faulting: when two plates slide past each other (fig. 7.15)