The answer would be b) She forgot your apply thermal paste between the CPU and the heat-sink and fan assembly
R₂ and R₃ can be replaced by:

The total R of the circuit is R₁+R₅+R₄ = 706 2/3
So the current in the circuit I=V/R is 100/(706 2/3) = 15/106 A
(I'm deliberately not trying to round the result)
The voltage drop over R₄ is V=I*R = 15/106 * 500 ≈ 70
So answer C would be my choice.
Answer and Explanation:
Omnidirectional antenna are those antennas which receives the signals from multiple directions equally.These are the antennas that cannot get the signal from a particular direction thus gives the low throughput.
To get high throughput, directional antennas should be installed because they receive the signal from a particular direction only .Thus the signal received from these antenna work for a certain area.Example-Television antenna at homes are directional antennas names as Yagi-uda antennas.