The right answer is B. viral load.
In medicine, it is more appropriate to use the term viral load rather than the viral count. In virologic diagnosis, viral load is the most commonly used term for physicians and biologists.
The viral load or viral titre is the number of copies of a virus (HIV, HBV ...) in a given volume of fluid (blood, sperm, saliva ...).
It is most often expressed in copies per milliliter, or on a logarithmic scale.
In the context of HIV, the measurement of the viral load is interesting for the follow-up of an already treated patient.
