Explanation:

To identify the atom, we use the given information: Mass number ($A$) = 14 and Number of neutrons ($N$) = 8. The number of protons ($Z$) in an atom is calculated as $Z = A - N$. So, $Z = 14 - 8 = 6$. An atom with 6 protons is Carbon (C), as the atomic number defines the element. Therefore, this atom is Carbon-14 ($^{14}\text{C}$). An isotope is an atom of the same element (same number of protons) but with a different number of neutrons (and thus a different mass number). Carbon-14 is an isotope of carbon. Option A (Isotope of oxygen) is incorrect because oxygen has 8 protons. Options C and D (Isobar of oxygen/carbon) are incorrect because isobars are atoms of different elements (different number of protons) but with the same mass number. While this atom has a mass number of 14, it is an isotope of carbon, not an isobar of oxygen or carbon (which would imply a different element with mass 14).