It makes an interpolation to represent them continuous, and it is not enough to replace lines with discrete markers

It makes an interpolation to represent signals as continuous, but systems are correctly represented

It makes an interpolation to represent them continuous, but they can be corrected by replacing lines with discrete markers

It makes an interpolation to represent system as continuous, but signals are correctly represented

That the root locus for a sampling period of 10 seconds is stable for more values of K, even though the approximation of the continuous response is much worse.