"M&N, a leading cosmetic company, recently launched a test marketing initiative for its line of cosmetics for preteens between the ages of 9 and 14 years. To promote the product, its marketing team undertook a campaign where it invited groups of preteens to try out the cosmetics in malls and conducted a session to obtain feedback from them. The feedback from the preteens helped the team understand the ideas that these preteens had about their products. Which of the following methods of collecting data did the marketing team of M&N utilize in this scenario?"a) Observational Researchb) Focus Groupc) Mathematical Modellingd) Experiemental Research