From the given options, select the pair of words which carries the same relationship to the given pair of words:

Cell : Nucleus

Atom : Proton

Here's why:

Cell : Nucleus describes a biological structure and its central component. The nucleus is the control center of a cell, containing DNA and responsible for directing its activities.

Atom : Proton similarly describes a fundamental particle and its essential component. Protons are the positively charged particles in the nucleus of an atom, defining its atomic number and contributing to its overall structure and stability.

Both pairs highlight the relationship between a complex structure and its central, essential component that plays a crucial role in its function and identity.