Concept:Problems of conducting a census are factors that make the counting of the population difficult or inaccurate.Explanation:High rate of rural-urban migration creates movement during the census period, causing people to be missed, counted twice, or placed in the wrong location.This reduces the accuracy of the census exercise.Poor geographical distribution of population, high birth rate, and poor town planning are not direct problems of conducting a census.Answer:A. high rate of rural-urban migration