What is the average atomic mass of Mg if the naturally occurring isotopes are ²⁴Mg , ²⁵Mg and ²⁶Mg Their masses and abundances are as follows:

Isotope Atomic Mass Isotopic abundance
²⁴Mg 23.98504 78.70%
²⁵Mg 24.98584 10.13%
²⁶Mg 25.98259 11.17%

A. 24.31
B. 25.68
C. 23.99
D. 24.98