Answer: Functional departmentalization
Explanation: In a functional departmentalization structure, the company tries to organize the employees into groups based upon the specific skills they possess. The activities performed by such groups are different from each other but the employees within groups performs the same task.
In the given case, the manager is dividing the company as per the purchase,serving and home delivery etc. It is evident that the grouping is done upon the specific activities to be performed.
Hence we can conclude that the correct option is B.