Given a rational number as input, name the set or sets to which it belongs: natural, whole, integer, and/or rational. For example, 3 would be a member of the natural, whole, integer, and rational sets; whereas -3.5 would be a member of the rational set, only. Return one of the following four options as your result: ['natural', 'whole', 'integer', 'rational'], ['whole', 'integer', 'rational'], ['integer', 'rational'], or ['rational'].