Use the results of the Bayes Information Criterion variable selection procedure for screening three explanatory variables in a proportional hazards model given in Table 13.17 to answer the following:

(a) Which two models are the best fitting models according to the Bayes Information Criterion?

(b) If there are no prespecified scientific reasons for including any of the explanatory variables in the model, which model should be selected as the final model?

(c) If there are scientific reasons for including the explanatory variable ????2 in the model, which model should be selected as the final model?