Which of the following price situations is illegal?

A、Anorganisationchargesdifferentpricestocustomersindifferentgeographicregionsduetohighertransportationcosts.
B、Anorganisationoffersalowentrypriceforabasicproduct,thenchargesmorefordesirableadditionalpartsorfunctions.
C、Anorganisationoffersvolumepurchasediscounts.
D、Organizationsdisplayingpricedifferentialsbetweenbusinesscustomersgiveonebusinesscustomeranunfairadvantageoveranother.