Concept:
The question tests classification based on biological function.
Step 1: Analyze each option.
Platelets → components of blood, help in clotting
Red blood cells → carry oxygen in blood
White blood cells → help in immunity
Nerve cells → part of nervous system, transmit impulses
Step 2: Identify the difference.
Platelets, RBCs, and WBCs are all components of blood.
Nerve cells belong to the nervous system.
Hence, Nerve cells is the odd one out.