Which type of white blood cells produces defensive proteins called antibodies?

Lymphocytes

Explanation:

White blood cells also known as leukocytes plays a very important role in maintaining the immunity of our body against foreign elements such as bacteria’s, viruses, pathogens etc.  

There are five type of white blood cell, namely –  

•neutrophils

•lymphocytes

•eosinophils

•monocytes

•basophils

Out of these five white blood cells, lymphocytes is responsible producing antibodies through its B and T cells that are produced in the bone marrow.

c. establishing proper sleep hygiene