A Workstaion - Computers is a powerful Computer that controls and manages
Other Computers on the network​

answer; ( blue box );

1. entrepreneur.com

2. wikipedia

only #2 represents an object at rest on a table.

in #1, there is no normal force due to the table; the object is accelerating downward.

in #3, the vertical forces are not balanced; the object is accelerating downward.

in #4, neither the vertical nor the horizontal forces are balanced. the object is accelerating upwards and to the right.