What is one source for the variation that drives natural selection?
a.
mutation
c.
over production
b.
cloning
d.
population shifts

select the best answer from the choices provided

a
b
c
d

Dmight be the correct answer

Order of filling levels and sublevels of electrons: 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²3f¹⁴5d¹⁰6p⁶for an element with 5 electrons in the 3d energy level: full configuration: 1s²2s²2p⁶3s²3p³.

A. burning woodcombustion is the process of burning something. make brainliest if correct