Human herpesvirus 4 is also known as the Epstein-Barr virus (EBV). Human herpesvirus 4 causes infectious mononucleosis (mono). The virus multiplies first in the epithelial cells and then the released progeny infects the memory B cells. The disease is manifested by sore throat and fever. The fever is mild for the whole day but peaks during the early hours of the evening.
The stage that scientists begin to ask questions and attempt to explain observations is A. forming hypotheses. This is because a hypothesis is basically a testable question about observations scientists make.
