Brent crude dropped to the lowest level in more than four months as the euro tumbled against the dollar after the European Central Bank unexpectedly cut its benchmark rate to a record low. The North Sea oil slipped 1.7 percent while West Texas Intermediate crude declined 0.6 percent. ECB President Mario Draghi pledged to keep borrowing costs low for an “extended period” in comments in Frankfurt . The euro fell the most against the U.S. currency in two years, reducing the appeal of dollar-denominated raw materials as an investment. The slide accelerated after the American economy grew more than forecast, bolstering bets the Federal Reserve may curb stimulus. “The stronger-than-expected U.S. GDP number and the unexpected ECB rate cut are strengthening the dollar,” said Tim Evans, an energy analyst at Citi Futures Perspective in New York. “A stronger dollar is generally associated with weaker commodity prices across the board […]