in finding will replace to find because –
when a Noun (difficulty) is used with a Prep. (in), the to - Inf. will not be used, - ing form (Gerund) of the Base Verb (find) will be used.
Look at the following examples :

Correct Option: B

in finding will replace to find because –
when a Noun (difficulty) is used with a Prep. (in), the to - Inf. will not be used, - ing form (Gerund) of the Base Verb (find) will be used.
Look at the following examples :

Supposing that he failed/If he failed will replace Supposing if he fails because –
Supposing and if cannot be used together.
The basic structure is as follows :

Correct Option: B

Supposing that he failed/If he failed will replace Supposing if he fails because –
Supposing and if cannot be used together.
The basic structure is as follows :

fined will replace have to pay a fine because – The sentence is in Passive Voice.
Look at the examples given below :
Mary mailed the letter. (Active Voice)

Correct Option: C

fined will replace have to pay a fine because – The sentence is in Passive Voice.
Look at the examples given below :
Mary mailed the letter. (Active Voice)

will replace would because –
When the Conditional Clause begins with If, the structure of the sentence will be as follows :

Correct Option: C

will replace would because –
When the Conditional Clause begins with If, the structure of the sentence will be as follows :

from going will replace to go because –
from (Prep.) is used for showing that something is prevented.
The structure will be as follows :

Correct Option: C

from going will replace to go because –
from (Prep.) is used for showing that something is prevented.
The structure will be as follows :