Which of the following compounds will form significant amount of meta product during mono-nitration reaction?

Aniline has a basic amino group ($$-NH_2$$). In the presence of strong acids, the lone pair on the nitrogen atom accepts a proton ($$H^+$$) to form the anilinium ion ($$-NH_3^+$$).

Aniline ($$-NH_2$$): Under normal conditions, the amino group is a powerful activating group and is ortho/para directing.

Anilinium Ion ($$-NH_3^+$$): Once protonated, the nitrogen carries a full positive charge. This makes it a strongly deactivating group that pulls electron density away from the ring via the inductive effect. Consequently, the anilinium ion is meta-directing.

Because a significant equilibrium concentration of the anilinium ion exists in the acidic nitrating mixture, the reaction yields a surprisingly high amount of the meta-isomer. A typical product distribution for the direct nitration of aniline is:

Para-product: ~51%, Meta-product: ~47% (Significant amount), Ortho-product: ~2%

While the other functional groups ($$-OH, -OCOCH_3, -NHCOCH_3$$) also have lone pairs, they are much less basic than the amino group in aniline.