In the condition myasthenia gravis, antibodies bind to and block certain receptors on muscle cells, preventing muscle contraction. This condition is best classified as an a. immunodeficiency disorder. b. exaggerated immune reaction. c. allergic reaction. d. autoimmune disorder.

Verified step by step guidance

1. Identify the key issue in the condition described: antibodies are binding to and blocking receptors on muscle cells.
2. Understand the role of antibodies in the immune system: normally, they help fight off pathogens, but in this scenario, they are mistakenly targeting the body's own cells.
3. Recognize that the condition involves the immune system attacking the body's own cells, which is characteristic of a specific type of disorder.
4. Determine the category of immune disorders that includes diseases where the immune system attacks the body's own tissues.
5. Match the characteristics of myasthenia gravis with the correct classification of immune disorders.