Which of the following statements selects from a data set only those observations for which the value of the variable Style is RANCH, SPLIT, or TWOSTORY?
a.where style='RANCH' or 'SPLIT' or 'TWOSTORY';
a.where style in 'RANCH' or 'SPLIT' or 'TWOSTORY';
a.where style in (RANCH, SPLIT, TWOSTORY);
a.where style in ('RANCH','SPLIT','TWOSTORY');