Answer: Option (A) is the correct answer.
Step-by-step explanation:
Atomic number is defined as the sum of total number of protons present in an element.
Whereas mass number is defined as the sum of total number of protons and neutrons present in an atom.
Also, when an atom is neutral in nature then its number of protons are equal to the number of electrons.
For example, atomic number of radium is 88 and mass number is 226.
Hence, number of neutrons can be calculated as follows.
Mass number = no. of protons + no. of neutrons
226 = 88 + no. of neutrons
No. of neutrons = 226 - 88
= 138
Thus, we can conclude that there are 88 protons present in radium-226 nuclide.