【单选题】

there are two major types of reserves used on projects. the _____ is for (usually major) scope changes that were not considered as part of

the original plan, whereas the _____ is to compensate for minor changes in estimating, escalation factors.
a. management reserve, unplanned allowance fund.
b. management reserve, contingency.
c. contingency fund, management reserve.
d. unplanned allowance fund, budgetary reserve.
e. unplanned reserve, planned reserve.