This sentence is pure meaning. You do not need to figure out anything else.
Since products in the chemical industry have extremely brief shelf lives, manufacturers of chemicals usually produce as much as possible in a short span of time,
Since X does one thing, this one thing (as per the sentence) had a start
and this was a trend begun by the early manufacturers of chemical products in the nineteenth century, which is continuing in twenty-first century markets.
blah blah blah
A.
and this was a trend begun by the early manufacturers of chemical products in the nineteenth century, which is
not necessary and. it breaks up the meaning we are looking for
B. which was a trend that began by the early manufacturers of chemical products in the nineteenth century and it is
the time was a trend . OFF
C. a trend begun by the early manufacturers of chemical products in the nineteenth century and
correct in the lineage and logic flow
D. a trend begun by the early manufacturers of chemical products in the nineteenth century, it is
it is in the end breaks the meaning. we ned AND to add up informations
E. which was a trend begun by the early manufacturers of chemical products in the nineteenth century and is
again like B
C is the answer