To answer the question regarding the components of a research design, we need to understand what a research design entails. A research design is a framework or blueprint for conducting research. It details the procedures for collecting, measuring, and analyzing data.

The primary components of a research design typically include:

• Comparison: This involves comparing different groups or conditions to understand differences or effects.
• Control: This ensures that the study conditions are kept constant, or that extraneous factors are controlled, to ensure the validity of the results.
• Manipulation: This refers to the deliberate alteration of variables to observe the effects on other variables, common in experimental designs.
• Generalization: This implies the extent to which the findings of the study can be applied to larger populations beyond the study sample.

Now, let's evaluate the options provided in the question:

• (a) Comparison: Yes, it is a key component of research design as it involves comparing groups or variables.
• (b) Control: Yes, essential for maintaining integrity in the research process by controlling other influencing factors.
• (c) Reactivity: This is not typically a component of research design. Reactivity refers to the influence that the observer's presence might have on the subjects, which is more related to observation biases.
• (d) Manipulation: Yes, a crucial component especially in experimental research designs where variables are manipulated.
• (e) Non-representativeness: This is typically a limitation or consideration rather than a component of a research design.
• (f) Generalization: Yes, considered a component as the findings should ideally be applicable beyond the specific study sample.

Based on the above analysis, the components of a research design from the given list are indeed (a) Comparison, (b) Control, (d) Manipulation, and (f) Generalization.

Therefore, the correct answer is (a), (b), (d) and (f).