The reaction schemes/images in Column I are not visible in the text you provided, so I infer the intended standard organic-nitrogen reactions from the matching options.

We need identify which mapping is chemically consistent.

From Column II:

• $(P)$ Racemic mixture
• $(Q)$ Addition reaction
• $(R)$ Substitution reaction
• $(S)$ Coupling reaction
• $(T)$ is not explicitly printed, but from such standard questions it is typically an elimination-related process or some distinct reaction type.

Now inspect the answer patterns:

• In all options, $(B) \to (T)$, so this is निश्चित/fixed and does not help discriminate.
• $(D) \to (R)$ in all options except none, so $(D)$ is definitely a substitution reaction.
• Main ambiguity is for $(A)$ and $(C)$.

1. Interpreting reaction $(A)$

For nitrogen-containing compounds, a very common reaction that is both substitution and coupling is diazonium salt chemistry:

1. Substitution: $\text{ArN}_2^+X^- \to \text{ArX},\ \text{ArOH},\ \text{ArCN},\ \text{etc.}$
2. Coupling: $\text{ArN}_2^+X^- + \text{activated aromatic ring} \to \text{azo compound}$

So if reaction $(A)$ involves an aryl diazonium salt, then it matches both: $(A) \to (R), (S)$

That eliminates options A and B.

2. Interpreting reaction $(C)$

A common nitrogen-compound reaction that gives both racemic mixture and addition reaction is nucleophilic addition to a planar carbonyl/iminium-type system creating a new chiral center, or addition across a multiple bond leading to a chiral amine product formed from either face.

Because attack occurs from both faces of a planar intermediate, a racemic mixture results, and the process is categorized as an addition reaction. Thus: $(C) \to (P), (Q)$

Among the remaining options, only D has this mapping.

3. Checking consistency of $(D)$

$(D) \to (R)$ corresponds to a substitution reaction, which is highly typical for many amine/diazonium reactions and is consistent with all plausible matchings.

4. Final matching

Therefore the correct complete match is:

This corresponds to Option D.

5. Comparison with stored answer

Stored correct answer = D.

My derived answer also = D, so they agree.