Below are descriptions of nine variables.

Select the THREE options that are categorical (but not ordinal) variables.

Select one or more:

proximity to work ('less than 1 mile', 'between 1 and 3 miles' or 'between 3 and 10 miles', 'more than 10 miles')

volume of bubble (in mm)

viral load (number of virus copies per ml of blood)

birth weight (in kg)

blood type ('O', 'A', 'B', 'AB')

number of children in the household ('none', '1 child', '2 children', '3 or more children')

preferred holiday type ('beach', 'skiing', 'sightseeing', or 'cruise')

type of exercise last taken ('running', 'cycling', 'swimming', 'gym session' or 'other')

reduction in symptoms ('none', 'some' or 'complete')