Question

which type of protein will fight disease?
insulin
antibodies
ligaments
genes

Explanation:

Antibodies are proteins produced by the immune system to identify and neutralize pathogens (such as bacteria and viruses), thus fighting diseases. Insulin is a hormone that regulates blood - sugar levels. Ligaments are connective tissues (not proteins in the context of fighting disease as asked here). Genes are segments of DNA that carry genetic information, not proteins that directly fight disease.

Answer:

antibodies