Multiple choice There was a ________ in the the situation in Ukraine when Putin met the Ukrainian PM. develop development developmental erosion Reveal answer Fill a bubble to check yourself B Correct answer Explanation The singular article 'a' must be followed by a singular noun. 'Development' is the correct noun form that fits the context of a new turn of events. 'Develop' is a verb, 'developmental' is an adjective, and 'erosion' does not fit the context.