a) In a super store, a customer selects the items from different racks, puts them in the shopping cart and takes them to sales counter. At sales counter, a sales officer takes the products from shopping cart aSuppose we have defined tables of database without defining primary keys of the respective tables? How can we access a unique record from a table in absence of primary key? Justify your answer with proper reasoning?rn for billing in busy hours. At the end of the day of the day, the sales officer generates daily sales summary on a separate page and gives it to the owner of the store. On weekly basis, purchase demand for those items is produces whose stock level is zero and given to the purchase officer. The store wants to computerize its system. What kind of input and output devices should be used by the company to implement the system? Justify your answer with proper reasoning?