In the depletion region of a diode :(A) There are no mobile charges(B…

The correct answer is Option (2) → (A), (C), (D) only

At a p-n junction the electrons of the n-side and the holes of the p-side diffuse across and recombine. They leave behind fixed (immobile) ionised donors on the n-side and ionised acceptors on the p-side, and this layer of fixed charge is the depletion region.

(A) There are no mobile charges — Correct. The free electrons and holes of this layer have moved away or recombined, so it is depleted of mobile charges.

(B) Equal number of holes and electrons exist, making the region neutral — Incorrect. The region is not neutral: its n-side carries positive donor ions and its p-side negative acceptor ions.

(C) recombination of holes and electrons has taken place — Correct. The carriers that diffused across the junction met carriers of the opposite kind and recombined, which is how the layer lost its free charges.

(D) Immobile charged ions exist — Correct. The ionised donors and acceptors are bonded in the crystal and cannot move.

(E) There are mobile charges — Incorrect. This contradicts (A).

NCERT (2026-27):
p-n Junction Formation – “… When an electron diffuses from n → p, it leaves behind an ionised donor on n-side. This ionised donor (positive charge) is immobile as it is bonded to the surrounding atoms. As the electrons continue to diffuse from n → p, a layer of positive charge (or positive space-charge region) on n-side of the junction is developed. … This space-charge region on either side of the junction together is known as depletion region as the electrons and holes taking part in the initial movement across the junction depleted the region of its free charges.”