The filterable agents were first purified in 1935, when Stanley was successful in crystallizing the _

Explanation

Option B is correct.Karl Landsteiner and Erwin Popper discovered the poliovirus in 1908. Landsteiner was an Austrian-American pathologist and immunologist, while Popper was an Austrian physician. They isolated the virus from the spinal cord of a child who had died of poliomyelitis. Stanley was the first scientist who crystallized tobacco mosaic virus in 1935.TMV is transmitted from infected plant to healthy plant through contact, such as by touching an infected leaf or by using the same tools on both infected and healthy plants. TMV can also be transmitted through the air, but this is less common.Baruch Blumberg, who discovered the hepatitis B virus (HBV) in 1967. Blumberg was an Australian-American physician and immunologist who was awarded the Nobel Prize in Physiology or Medicine in 1976 for his discovery. Wilson Smith, Christopher H. Andrewes, and Patrick P. Laidlaw are credited with the discovery of the influenza virus in 1933. They were working at the National Institute for Medical Research in London, England, when they isolated the virus from the throat washings of a patient with influenza.