Tilly Identifies Two Mechanisms That Produce "Durable" Inequality, Exploitation and Opportunity

Tilly identifies two mechanisms that produce "durable" inequality, exploitation and opportunity hoarding. What is the latter and how does it relate to exploitation?

A) The deprivation of access of other groups or categories of people to valued resources. To have access, one must exchange something (e.g. work, money) for it (i.e. be exploited) .
B) Valued resources, such as money and labor, which are exchanged for what one "buys," which can be anything from consumer goods to police protection (that is, exploitation) .
C) Those things people need, which can be determined by race and gender and what they will do anything for.
D) Opportunity hoarding is the pool of jobs that can be held back and sold, much like in market capitalism, for anything a have wants from a have not.