That is an essential modifier. An essential modifier is used to give information that is necessary to recognize the subject.

Which is an non essential modifier that modifies the legitimate noun before the comma

The road, which goes on for 24 miles, has a toll bridge - here "goes on for 24 miles" is not required i.e. if we remove this bit the sentence would not affected.

The House that is located at 24, Pennington lane is owned by Mary. - here that provides information that is required to recognize the house owned by Mary.

-ing modifiers modify the entire preceding clause and are attributed to the subject of that clause.

Thus in the question option C is correct.

Your query --> , which includes modifies term and not posts held by the Senator.


Hope it helps.

mohit11 wrote:That is an essential modifier. An essential modifier is used to give information that is necessary to recognize the subject.

Which is an non essential modifier that modifies the legitimate noun before the comma

The road, which goes on for 24 miles, has a toll bridge - here "goes on for 24 miles" is not required i.e. if we remove this bit the sentence would not affected.

The House that is located at 24, Pennington lane is owned by Mary. - here that provides information that is required to recognize the house owned by Mary.

-ing modifiers modify the entire preceding clause and are attributed to the subject of that clause.

Thus in the question option C is correct.

Your query --> , which includes modifies term and not posts held by the Senator.


Hope it helps.

Can you also help me with a couple of other queries i have posted today in SC

Some thoughts here

1. The question is not primarily linked to essential or non-essential modifiers. There are some other issue with using 'which' or 'that' here.

2. 'which' is modifying to 'term' in C while we need to modify to posts. -> so C incorrect

3. the other problem is the literal meaning of 'included vs including'.

When we say
..X., which include A, B and C -> It means X include A , B and C
[e.g. ... wines, which include water, grapes and ethyl acid. ]

X, including A, B and C -> it means that A, B, C are examples of X
[e.g. ....wines, including Blackstone, kingfisher and Korbel ]

So usage of including makes sense.

A similar discussion you can see :
https://www.beatthegmat.com/stone-age-t36393.html