The process of fertilization of a human egg can be confirmed by the...

In human females, the secondary oocyte is arrested in the metaphase II stage of meiosis II before ovulation.

The completion of meiosis II occurs only when a sperm enters the secondary oocyte during fertilization.

Upon the entry of the sperm, the secondary oocyte completes its second meiotic division, resulting in the formation of a large ovum (ootid) and a small second polar body.

Therefore, the presence of the second polar body is a definitive confirmation that the process of fertilization has occurred.

Answer: $2^{nd}$ polar body