Concept:
Certain verbs require specific prepositions. The verb deal is commonly followed by the preposition with when referring to handling people, situations, or problems.
Step 1: Recall the standard expression.
\[
\text{deal with somebody}
\]
means
\[
\text{handle or manage somebody}
\]
Step 2: Apply it to the sentence.
It is really difficult to deal with those people who do not want to listen to others.
Step 3: Eliminate incorrect options.
• deal at --- incorrect
• deal about --- incorrect
• deal after --- incorrect
• deal with --- correct expression
Hence,
\[
{\text{Option (D)}}
\]