<prompt> Which of the folowing is used to assess the communicability of a disease following the exposure to the primary case?Secondary attack rateGeneration timeSerial intervalIncubation period  <response>: Secondary attack rate is defined as the number of the exposed persons developing the disease within the range of the incubation period, following exposure to the primary cause. A measure of infectivity is the secondary attack rate. It reflects the degree of contagiousness of a communicable disease, and has been used in assessment of the effectiveness of control measures. 