Option 1: Edward Jenner is known as the "Father of Immunology". He is acknowledged for introducing the concept of vaccinations, more specifically, the smallpox vaccine – the world`s first vaccine. Therefore, he is indeed the pioneer who introduced immunization to the medical world.

Option 2: Robert Koch, a formidable name in microbiology, improved the scientific rigor in medical investigations and contributed to identifying the causative agents of tuberculosis, cholera, and anthrax, but he did not introduce immunization.

Option 3: Robert Hooke was a prominent figure in 17th century science. Known for his work in various fields like physics, microscopy, and paleontology, his contributions didn`t include immunization.

Option 4: Carl Linnaeus was a notable botanist, zoologist, and physician who developed modern taxonomy – the system of naming organisms. While his work laid foundations of modern biological nomenclature, it was not associated with the concept of immunization.