Osteocytes
Malpighian layer of the skin
Liver cells
Neurons
Neurons have the lowest likelihood of being replaced by new cells. Neurons, which are specialized nerve cells, generally lack significant regenerative capabilities, especially in most areas of the adult human brain and spinal cord. In contrast:
In summary, neurons are the least likely to be replaced by new cells, while the other cell types mentioned exhibit varying degrees of replacement and regeneration mechanisms.
∴The correct option is (D): Neurons.

Given below are two statements:
Statement I: Transfer RNAs and ribosomal RNA do not interact with mRNA.
Statement II: RNA interference (RNAi) takes place in all eukaryotic organisms as a method of cellular defence.
In the light of the above statements, choose the most appropriate answer from the options given below:
The human nervous system is responsible for controlling and coordinating all the activities of the human body.
The Central Nervous System (CNS) comprises the brain and spinal cord.
The Peripheral Nervous System (PNS) comprises sensory/motor neurons and ganglion.