Answer
NONRESPONSE BIAS = only 5029 of the 45,956 calls were completed.
SELECTION BIAS = only the completed calls were included in the sample and thus the uncompleted calls had no chance to be in the sample.
Work Step by Step
Selection or undercoverage bias will exclude part of the population, measurement or response bias will use a method that gives different values from the true value and nonresponse bias is the results of not having data for everybody in the sample.
