Name and City cannot be specified as Primary Key, because these columns can have duplicate values for different records.
Detailed Answer :
In the table Custld can be specified as primary key because Custld foe every customer is unique. But Name, City, and Mobile No. cannot be specified as primary key because these details can be common for some customers while for primary key uniqueness is necessary.
OR
Table: A table has records (rows) and fields (columns).
Record: Contains specific data, like information about a particular employee or a product.
Field: Contains data about one aspect of the table, such as First Name or E-mail Address.
Example:
