When elements are separated by a comma in SELECT, then it's just different elements.
When elements are separated by a comma in FROM, then it's the cross product of elements, and by "elements", here we mean relations.
Employee
|
Department
|
|
RAMA
|
Mechanical
|
|
GOPI
|
Electrical
|
|
SINDHU
|
Computer
|
|
MAHESH
|
Civil
|
|
|
Department
|
OT_allowance
|
|
Mechanical
|
5000
|
|
Electrical
|
2000
|
|
Computer
|
4000
|
|
Civil
|
1500
|
4 unique values from Table 1 matches with that of table 2 under the common attribute name Department
So, Option B