Final answer:
Acute rheumatic fever is a Type II hypersensitivity reaction, where antibodies target the body's own tissues, causing inflammation and damage.
Step-by-step explanation:
Acute rheumatic fever is classified as a Type II hypersensitivity reaction. This type of hypersensitivity involves the immune system incorrectly targeting the body's own cells. In the case of acute rheumatic fever, antibodies produced by the immune system in response to a prior infection with Streptococcus bacteria (such as strep throat) mistakenly attack heart, joint, skin, and brain tissues, leading to inflammation and tissue damage.