Hi Kevin, 

Objects thrown up by a vehicle and objects falling from an aircraft are covered.  Other "falling objects" are not covered.  The question asks which peril is not covered.  The correct answer is "Falling objects EXCEPT falling objects from an aircraft".  In this case the correct answer is "A". 

"Sinkhole collapse" is a little confusing because it is the "retired" terminology for Catastrophic Ground Collapse - it means the same thing.  I have gone into the course and attempted to correct every time the term "sinkhole" is used, but I keep finding new places. 

Please let me know if you have other questions.

Jan