The section presents a question related to atomic structure, specifically focusing on which subatomic particle is responsible for the chemical properties of an atom. The options provided are:

A. Proton  
B. Neutron  
C. Electron  
D. All  

The key topic is the role of subatomic particles (protons, neutrons, and electrons) in determining the chemical behavior of atoms, with a particular emphasis on identifying the correct particle responsible for these properties.