Step 1: Understanding the Concept: 
The question asks to identify the type of market segmentation based on the given criteria for a target market. Market segmentation is the process of dividing a broad consumer market into sub-groups based on shared characteristics. 
Step 2: Detailed Explanation: 
Let's analyze the given criteria: "female wage earners in the age group of 25-45 years". 
    
 female - This is segmentation by gender.
    
 wage earners - This is segmentation by occupation or income level.
    
 age group of 25-45 years - This is segmentation by age.
Now, let's look at the types of segmentation: 
    
 (1) Demographic Segmentation: This involves dividing the market based on statistical characteristics of a population, such as age, gender, income, occupation, education, marital status, and family size. The criteria used by the designer (gender, occupation/income, age) fall squarely into this category.
    
 (2) Geographic Segmentation: This involves dividing the market based on location, such as country, city, or climate.
    
 (3) Psychographic Segmentation: This involves dividing the market based on lifestyle, values, personality, and interests.
    
 (4) Behavioural Segmentation: This involves dividing the market based on consumer behavior, such as purchasing habits, brand loyalty, and product usage.
Step 3: Final Answer: 
Since the target market is defined by age, gender, and occupation, the type of segmentation used is Demographic Segmentation.