Choose the alternative that fills in, correctly and...

Read the paragraph below to answer questions 16 to 18.

The alarm ______ Europe ______ the discovery ______ horse meat ______ beef products escalated again Monday, when the Swedish furniture giant Ikea withdrew an estimated 1,670 pounds ______ meatballs ______ sale ______ 14 European countries. Ikea acted after authorities in the Czech Republic detected horse meat in its meatballs. The company said it had made the decision even though its tests two weeks ago did not detect horse DNA. Horse meat mixed with beef was first found last month in Ireland, then Britain, and has now expanded steadily across the Continent. The situation in Europe has created unease among American consumers over ______ or not horse meat might also find its way into the food supply in the United States.

(The New York Times, 2/25/2013)