Reasons for Sorting Materials into Groups
Sorting materials into groups serves multiple purposes, including:

Understanding Properties
- By sorting materials into groups based on their properties, such as color, size, shape, and texture, it becomes easier to study and understand their characteristics.
- This categorization allows scientists and researchers to identify patterns and similarities among materials within the same group, leading to a better understanding of their properties.

Convenience
- Sorting materials into groups also offers convenience in various tasks. For example, in a laboratory setting, having materials organized into groups makes it easier to locate specific items when needed.
- It also helps in conducting experiments or investigations more efficiently, as materials with similar properties can be grouped together for comparative studies.

Combination of Both (a) and (b)
- The main purpose of sorting materials into groups is to combine the benefits of studying their properties and convenience.
- By categorizing materials based on their properties, not only do we gain a deeper understanding of the materials themselves, but we also make our work more organized and efficient.
Therefore, the correct answer is option 'C' - both (a) and (b). Sorting materials into groups helps us study their properties effectively while also providing convenience in various tasks related to handling and using different materials.