Under which of the following reaction conditions, aniline gives p-nitro derivative as the major product?

a. Acetyl chloride/pyridine followed by reaction with conc. H2SO4 + conc.HNO3
b. Acetic anhydride/pyridine followed by conc. H2SO4 + conc. HNO3
c. Dil. HCI followed by reaction with conc. H2SO4 + conc. HNO3
d. Reaction with conc. HNO3 + conc. H2SO4

  

Choose the correct option
1. (a, b)
2. (b, c)
3. (c, d)
4. (a, d)

Aniline or reaction with acetyl chloride or acetic anhydride in the presence of pyridine produces N-acetyl aniline which is an ortho, para directing group which on further reaction with the nitrating mixture (conc. HNO3 + conc. H2SO4) produces p-nitroaniline preferentially as shown below.