Observe the given table carefully and answer the following questions:
| Pan No | Name | Phene no | Address |
| CTZPW123A | Rajesh Kumar | 9599123456 | WZ11-Rajouri Garden, Delhi |
| ABWQ2341B | Hemant Kumar | 9812345678 | Modem Apartments, Pitampura, Delhi |
| DERA9786T | Naveen Sharma | 7868654235 | CA22, Sector 21 Rohini, Delhi |
| PARD3457L | Sourabh Verma | 8933217645 | JD 61, Sector 20, Gurgaon |
| GDTT8762P | Nishant Kumar | NULL | Modern Apartments, Pitampura, Delhi |
| MERT2376G | Hemant Kumar | 9811110891 | F40, Sector 19, Rohini, Delhi |
(i) Name the column that might have a primary key constraint. justify your answer.
(ii) Name the column that might have a Unique constraint. Justify your answer.
