Sentence structure is a casualty in this topic.
(A) Data collected by high-end geiger counters has been observed by physicists, stating that the Earth's atmosphere has –
The problem is that the ambiguity created by the present participle –stating- Who does it modify? Being an adverbial modifier, it need not necessarily modify the physicists – It may modify the Data
(B) Data collected by high-end geiger counters has been observed by physicists, and they state the Earth's atmosphere as having -----
state the earth’s as having –this expression defies any meaningful structure.(C) After observing data collected by high-end geiger counters, physicists state that the Earth's atmosphere has ---
Proper modification -looks like the best choice;
(D) After observation of data, collected by high-end geiger counters, physicists state the Earth's atmosphere as having ----
physicists state the Earth's atmosphere as having—as having become denotes a finished affair, whereas thinning is still an ongoing factor(E) After data collected by high-end geiger counters was observed by physicists, who state that the Earth's atmosphere has---
The sentence is a fragment