What type of classification is used when data is grouped by characteristics like gender or marital status?

Qualitative classification

The correct answer is Option 3: Qualitative classification

Qualitative classification is used when data is grouped by non-numeric characteristics such as gender, marital status, nationality, etc.

"Sometimes you come across characteristics that cannot be expressed quantitatively. Such characteristics are called Qualities or Attributes. For example, nationality, literacy, religion, gender, marital status, etc. They cannot be measured. Yet these attributes can be classified on the basis of either the presence or the absence of a qualitative characteristic. Such a classification of data on attributes is called a Qualitative Classification. In the following example, we find population of a country is grouped on the basis of the qualitative variable “gender”. An observation could either be a male or a female."