The correct answer is D. Aluminium.
A donor atom is an atom that can donate an electron to a semiconductor. This can be done by adding the atom to the semiconductor, or by doping the semiconductor with the atom. When a donor atom donates an electron, it creates a hole in the semiconductor. This hole can then be used to carry current.
Phosphorus, antimony, and arsenic are all donor atoms. They can all be added
to semiconductors to create n-type semiconductors. N-type semiconductors have an excess of electrons, which makes them good conductors of electricity.Aluminium is not a donor atom. It is a group 3 element, and it has three valence electrons. When aluminium is added to a semiconductor, it does not donate an electron. Instead, it forms an ionic bond with the semiconductor. This bond does not create a hole in the semiconductor, and it does not make the semiconductor a good conductor of electricity.