B D A C
First, you need to find the independent /starting sentence, which is the sentence that doesn’t refer to other sentences such as events, people or time et cetera.
With that being said, let’s look at which sentence(s) (can be more than one independent sentence) can or can’t be considered as independent /starting sentence.
A is not independent sentence as it refers to the “total waste stream”, which is “the current global production” in D. C uses consequently, therefore it also is not independent sentence.
Now we are left with B and D. B talks about the electrical equipment with their ever-decreasing lifespan which is the cause of E-waste mentioned in D, so it becomes quite clear that B is our starting sentence, and followed with D.
After D, it is A. The subject here is “In Europe”, which connects the object of D “with most E-waste being produced in Europe, the United States and Australasia”.
B D A
Finally, we have C.
B D A C