Doug, a frequent visitor of online auction sites, uses two different accounts-one to place a low bid and the other to place a very high bid on the desired item. this leads to other bidders dropping out of the auctionhe then retracts the high bid and wins the item at the low bid. this form of e-auction fraud is known as
a) shill biddingb) bid luringc) rafter biddingd) mystery biddinge) bid skimming

Shill biding

Explanation: In simple words, it refers to a fraud in which the individual manipulates the bid by dealing with two or more accounts handled by his friends or himself etc.

In the given case, Doug is a frequent visitor and is placing low bids from one account and high bids from the other and step back from the high bid after winning to get it at a low price.

Hence from the above we can conclude that the correct option is A.

convection currents in magma drive plate tectonics. the answer is true.