Based on your knowledge of chordate evolution, which of the following groups is MOST closely related to you (i. e., with whom have you most recently shared a common ancestor)?

a. Sea lamprey Coelacanth (a lobe-finned fish)
b. Gray treefrog (an amphibian)
c. Mudskipper (a ray-finned fish)
d. Burmese python (a snake)

The correct option is d) Burmese python (a snake)

Explanation:

Evolutionary study of chordates show that the earliest chordates were all marine animals. The evolution of marine chordates resulted in the formation of amphibians which were a transition state between marine animals and land animals. From the amphibians, reptiles and birds evolved. Studies show that reptiles and birds evolved into mammals such as the humans. Hence, as Burmese python is a reptile it will share a more common ancestor with humans.

the relative atomic mass of an element is the mass of one atom of that element, relative to 1/12th of the mass of a  1212c atom. to convert to an absolute mass in kg, it is necessary to multiply by  1.661×10−271.661×10−27.

the relative atomic mass is roughly equal to the number of neutrons, plus the number of protons, in the nucleus of the atom.

for elements with more than one stable isotope (different types of nucleus with different numbers of neutrons but the same number of protons), the quoted mass is usually the average mass, weighted by the relative abundance of the different isotopes.