in a hotel will replace in the hotel because –
the(Def. Art.) is used with a particular/specific Noun
Look at the examples given below :
They are staying at the Taj Palace.
We stayed in a hotel for the night.

Correct Option: C

in a hotel will replace in the hotel because –
the(Def. Art.) is used with a particular/specific Noun
Look at the examples given below :
They are staying at the Taj Palace.
We stayed in a hotel for the night.

leaves will replace left because –
When the tense in the Main clause is will/going to (referring to the future), the tense in the Conditional Clause will be in Simple Present.
This letter will reach him ® Main clause

Correct Option: B

leaves will replace left because –
When the tense in the Main clause is will/going to (referring to the future), the tense in the Conditional Clause will be in Simple Present.
This letter will reach him ® Main clause

since/from time immemorial will replace since times immemorial because –
since is used for referring back to a previous point in time and it is used as a Preposition with a date, a time or a Noun Phrase.
from/since time immemorial (Idiom) : for longer than any one can remember.
Look at the examples given below :
Her family had farmed that land from time immemorial.
My home town has had a parade on the fourth of July since time immemorial.

Correct Option: C

since/from time immemorial will replace since times immemorial because –
since is used for referring back to a previous point in time and it is used as a Preposition with a date, a time or a Noun Phrase.
from/since time immemorial (Idiom) : for longer than any one can remember.
Look at the examples given below :
Her family had farmed that land from time immemorial.
My home town has had a parade on the fourth of July since time immemorial.

whom will replace who because –
who refers to the subject of a sentence whereas
whom refers to the Object of a sentence.
If the Pronoun can be replaced by he, we use who and if it is replaced by him, we use whom
Look at the examples given below :

Correct Option: B

whom will replace who because –
who refers to the subject of a sentence whereas
whom refers to the Object of a sentence.
If the Pronoun can be replaced by he, we use who and if it is replaced by him, we use whom
Look at the examples given below :

more lonely/lonelier will replace more lonelier because –
Use of Double Comparatives is incorrect.
Look at the examples given below :
He ran faster than his friend. ( )
He ran more faster than his friend. (×)
The very word Comparative means that two objects are being compared against each other.
Hence, I am more lonely/ lonelier is the right usage

Correct Option: A

more lonely/lonelier will replace more lonelier because –
Use of Double Comparatives is incorrect.
Look at the examples given below :
He ran faster than his friend. ( )
He ran more faster than his friend. (×)
The very word Comparative means that two objects are being compared against each other.
Hence, I am more lonely/ lonelier is the right usage