The correct answer is option 'B': 200-300 million sperms are released in a single insemination.

Insemination is the process of introducing semen into the female reproductive tract to fertilize an egg. Sperms are the male reproductive cells that are necessary for fertilization to occur. During ejaculation, millions of sperms are released into the vagina. However, only a small fraction of these sperms are able to reach the egg and successfully fertilize it.

There are several factors that contribute to the large number of sperms released during insemination:

1. Sexual arousal: Sexual stimulation leads to the release of hormones that stimulate the production of sperms in the testes. This ensures that a large number of sperms are available for fertilization.

2. Semen volume: Semen is the fluid that carries the sperms. It is composed of secretions from the testes, seminal vesicles, prostate gland, and bulbourethral glands. The volume of semen released during ejaculation can vary, but on average, it is around 2-5 milliliters. This volume contains millions of sperms.

3. Sperm production: Sperms are continuously produced in the testes through a process called spermatogenesis. This process takes approximately 64-72 days from the initial production of sperm cells to their maturation. The testes produce a large number of sperms each day, ensuring a constant supply of viable sperms for insemination.

4. Sperm motility: Motility refers to the ability of sperms to move and swim towards the egg. Only motile sperms are capable of fertilizing the egg. To ensure successful fertilization, a large number of motile sperms are released during insemination.

However, despite the large number of sperms released, only a few are able to reach the egg. The journey of sperms from the vagina to the fallopian tubes is challenging, as they have to navigate through the cervix, uterus, and fallopian tubes. Additionally, the acidic environment of the vagina and the immune response of the female reproductive tract can hinder the survival and motility of sperms.

In conclusion, the number of sperms released during insemination is around 200-300 million. This large number is necessary to increase the chances of successful fertilization, as only a small fraction of sperms are able to reach and fertilize the egg.