Which process can be described as two cell divisions, genetic variation, and haploid cells?
a. meiosis
b. mitosis
c. binary fission
d. fertilization

The correct answer is option A, meiosis

Reason -

In a meiosis cell division the number of chromosomes usually reduces by half of its original number. It helps in the production of gametes—sex cells, or sperm and eggs. In the phase I of meiosis, diploid cell is formed while in phase II of meiosis, haploid cell is formed.  Meiosis produces sex cells which are responsible for causing the genetic variation.

the earth is thought to have been formed about 4.6 billion years ago by collisions from a cloud of hydrogen, helium, rock, ice and other materials. these were pulled together by gravity to form objects in and around earth like- asteroids and small early planets called planetesimals.

so, the best possible answer to this question will be option d- to harden materials to form different parts of earth’s layers