The atomic mass and abundance of Cr-50 is 49.946 amu and 4.3%. The atomic mass and abundance of Cr-52 is 51.941 amu and 83.8%. The atomic mass and abundance of Cr-53 is 52.941 amu and 9.5%. The atomic mass and abundance of Cr-54 is 53.939 amu and 2.4%. Which is the average atomic mass of chromium?
a. 53.94 amu
b. 52.19 amu
c. 52.00 amu
d. 51.94 amu