The yellowish fluid "colostrum" secreted by mammary glands of mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant. This type of immunity is called as:

The correct option is A Passive immunity
Acquired immunity or adaptive immunity is the immunity that an individual acquires during his/her lifetime.

Acquired immunity is of two types:

• Active immunity is a type of immunity which is acquired by the organism upon being exposed to an antigen. It results in the production of antibodies specific to the antigen.
• Passive immunity is when ready-made antibodies are directly given to an individual.
  • Colostrum is the breast milk produced in the first few days after the delivery. This milk is rich in antibodies such as IgA. This type of immunity acquired by the infant is an example of passive immunity.

Unfortunately, it has been noticed that sometimes either due to genetic factors or other unknown reasons, the immune system goes haywire and attacks the body's self-cells and destroys them. This is known as autoimmunity.