Hello Niner,

Please use the Spoiler next time to hide the answers. Also, do make sure you write remaining choices also so it would be better to explain it to you.

Explanation : The main clause here is " Emily Dickinson's letters to Susan Huntington Dickinson [spoiler](when)[/spoiler] outnumber her letters to anyone else.

Now, if you see the spoiler, the part (when) consists of the secondary clause --->It indicates when did that happen?

ans is "which were written over a period beginning a few years before Susan's marriage to Emily's brother and ending shortly before Emily's death in 1886"

Hence, "Emily Dickinson's letters to ..." correctly modifies "outnumber her letters to anyone else"

Hope you get it

Niner710 wrote:Emily Dickinson's letters to Susan Huntington
Dickinson were written over a period beginning a few
years before Susan's marriage to Emily's brother and
ending shortly before Emily's death in 1886.
outnumbering her letters to anyone else.

OA is (E)

(E) Dickinson, which were written over a period
beginning a few years before Susan's marriage
to Emily's brother and ending shortly before
Emily's death in 1886, outnumber

I don't understand the "which were written over a period...etc" here. It seems like it is modifying Susan Huntington Dickinson which would seem incorrect. Is which modifying the whole clause then?(Emily Dickinson's letters to Susan Huntington Dickinson) I thought only an -ING form could do that. Any help would be great. Thanks!

Here which should refer to letters... because there is a WERE after which ...
So which should refer to a noun which agrees in number also...

Thus which doesn't always refers to the noun preceding it..
it refers to a noun which should agree in verb also...

Hope it helps...

I read it somewhere in BTG post.. i think it was Ron's post about use of "which"...

https://www.beatthegmat.com/which-usage-t42599.html

please refer to Ron's post