A typical serial cable it has transfer information from between 2 devices using a serial communication protocol. The form of connectors it depends to particular serial port to be used.
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-Charlie
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.
The gears and mechanism's sudden movements make the noises
This is 100% f a l s e !!