Atom A has an atomic number of 19 and mass number of 40. Atom B has an atomic number of 20 and a mass number of 40. Which of these is an accurate statement?

A) Atom A has more protons than Atom B.
B) Atom A has one less proton and one more neutron than Atom B.
C) Atom A has an extra nucleon compared to Atom B.
D) Atom A has one more proton and one more electron than Atom B.