Final answer:
The random alignment of homologous chromosomes on the metaphase plate during meiosis ensures independent assortment.
Step-by-step explanation:
The process occurring during meiosis that ensures independent assortment is the random alignment of homologous chromosomes on the metaphase plate (option A).
During prophase I of meiosis, homologous chromosomes pair up and exchange genetic material in a process known as crossing over.
Then, during metaphase I, the homologous chromosomes randomly align on the metaphase plate, leading to independent assortment.
This means that each homologous pair of chromosomes has an equal chance of lining up on either side of the metaphase plate, resulting in unique combinations of chromosomes in the gametes.