Do all the protons,electron and neutrons of atoms of different element are same???

Question 07

Two atoms are said to be isobars if ?

(a) They have same atomic number but different mass number

(b) They have same number of electrons but different number of neutrons

(c) They have same number of neutrons but different number of electrons

(d) Sum of the number of protons and neutrons is same but the number of protons is different

Two elements having same number of protons and electrons but different number of neutrons