Ok, remove everything that have "forcing" at the end...
A The spectacular disintegration of a comet last year in full view of ground- and space-based telescopes provided new insights into how comets form and may thus force
C When a comet's spectacular disintegration occurred in full view of ground- and space-based telescopes last year, it provided new insights into how comets form and thus may possibly force
- out, it is not the disintegration that will force more studies... infact the new information will..
E Last year, in full view of ground- as well as space-based telescopes, the spectacular disintegration of a comet has provided new insights into how comets form and may thus force
Last year, is modifying the full sentence. There is no chronology of events. If you OG question in which chronology is mentioned.. for example, the question that mentions about the destruction and damage of buildings, it makes clear that things/actions need to be in sequance. What happened first, what is happening and what will happen...
A is a good choice. A says, the disintegration happened, we got some information and it will trigger new research.
hope it helps.