One of the holes of the fossil record is the absence of well

One of the holes of the fossil record is the absence of well-preserved bird
One of the holes of the fossil record is the absence of well-preserved bird feathers from the period that is likely_______with the mass extinction of dinosaurs.
A.to end B.to be ending C.to have ended D.to be ended.
请解释一下 .谢谢.