T cells. When HIV arrives in the lymph nodes – around 24 to 48 hours after exposure – they activate other immune cells, such as CD4 t-cells, HIV's primary target.
Answer:
Option (3).
Explanation:
Mark recapture method is used for the estimation of population size of an area. The individuals are identified by some mark on them. The formula of mark recapture method is
N = M * C/ R
Here, N is the number of the individuals, M is the individuals are marked and captured, C is the individual captured again with mark or non mark and R is recaptured marked individual.
The individual with 200 population, 20 are marked for the first time represent the large population size.
Thus, the correct answer is option (3).
