Final answer:
The shared property that belongs in the region marked 'B' on the Venn diagram comparing protons with electrons is 'is found in the nucleus'.
Step-by-step explanation:
The shared property that belongs in the region marked 'B' on the Venn diagram comparing protons with electrons is is found in the nucleus.
A proton is a positively charged particle that resides in the nucleus of an atom, while an electron orbits the nucleus in different energy levels called electron shells. Therefore, the property of being found in the nucleus is shared by protons and not by electrons, placing it in the region marked 'B'.