To answer this question, you need to understand the concept of Design of Experiments (DOE).
Option A) Screening Experiments - This option is incorrect because screening experiments are used to identify the most important factors or variables in a process. They are typically used when there are a large number of factors to consider, and the goal is to reduce the number of factors for further analysis.
Option B) Fractional Factorials - This option is incorrect because fractional factorials are used when there are a large number of factors to study, but it is not feasible or practical to conduct a full factorial experiment. Fractional factorials allow for studying a subset of the factors and their interactions.
Option C) Full Factorials - This option is correct because full factorials are used to study all possible combinations of factors and their interactions. This design is used when the number of factors is small, and it is feasible to evaluate all possible combinations.
Option D) None of the above - This option is incorrect because the correct answer is option C, Full Factorials.
The correct answer is C) Full Factorials. This option is correct because it is used to study the vital few X variables and all possible interactions in Design of Experiments.