In the process of artificial insemination (AI), the correct option is number 3, which states that only sperm is introduced into the uterus of the female.

Option 1, which states that only the egg is introduced into the uterus, is incorrect. In AI, the egg is not introduced into the uterus, as it is typically collected from the female and fertilized outside of the body using sperm.

Option 2, which states that a fertilized egg is introduced into the uterus, is also incorrect. In AI, the goal is to introduce sperm into the uterus to increase the chances of fertilization occurring naturally within the female`s reproductive system.

Option 4, which states that both the egg and sperm are introduced into the uterus, is incorrect. In AI, only sperm is introduced into the uterus, as mentioned in the correct answer. The fertilization of the egg typically occurs outside of the body through techniques such as in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

To summarize, in artificial insemination, only sperm is introduced into the uterus of the female.