Why Are Arbitrage Opportunities Short-Lived

Why are arbitrage opportunities short-lived?

A) Arbitrage opportunities need a lot of information processing, which is very slow to arrive.
B) Prices will fluctuate up and down as traders take advantage of the opportunity, resulting in the net present value (NPV) fluctuating between positive and negative values.
C) Once investors take advantage of the opportunity, prices will respond so that the buying and selling price become equal.
D) Financial market regulations will kick in to restrict trade and effectively shut the opportunity down.