Questions

Answer A is incorrect because project managers are not effectively utilized if they are always scheduling and coordinating resources for daily operations. Answer B is incorrect because project managers are not the best resource for providing estimates on daily operations and time allocations;people doing the actual work are the best resources. Answer D is incorrect because you do not specify different phases of ongoing operations.

Ethernet uses Bus topology.

RADAR - RAdio Detection And Ranging.

A radar system consists of a transmitter producing electromagnetic waves in the radio or microwaves domain, a transmitting antenna, a receiving antenna (often the same antenna is used for transmitting and receiving) and a receiver and processor to determine properties of the objects. 

Radar is an object-detection system that uses radio waves to determine the range, angle, or velocity of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain.

Radio waves from the transmitter reflect off the object and return to the receiver, giving information about the object's location and speed.

In token Ring , hub is called Multistation Access Unit(MAU).

Hydroelectricity is electricity produced from hydropower i.e, water.