Which among the following types of variable can NOT be rank ordered?

A nominal variable cannot be rank ordered because its categories are mere labels with no inherent order.

An ordinal variable can be ranked, since its categories fall in a meaningful sequence.

An interval variable is ordered and has equal spacing between adjacent values.

A ratio variable is ordered, equally spaced and carries a true zero point.

Gender, religion and blood group are typical nominal categories without rank.

The four scales rise in information from nominal through ordinal and interval to ratio.