Which of the following statements are true? Check all that apply$\mathrm{.}1$ pointIn a hierarchical description, only blocks at the higher level of hierarchy $($n$-$th level$)$ can be described functionally.The functional description of a digital system depicts its internal structure.The functional description of a system specifies the relationship between inputs and outputs.Any block in a digital circuit can be described hierarchically until a level of simplicity that allows its synthesis using a predefined catalog of components is achieved$\mathrm{.}2.$Question $2$In a stress test for elite athletes a physical system is used to measure the performance of the individual. Indicate which of these signals are analog signals:$1$ pointRespiratory Rate Type: Numerical; Range: integers from $8$ to $40.$ Temperature Type: Temperature, Range: from $18$C to $22$C $($only integer and half$-$integer values are measured$)$O$2$ Saturation Type: Voltage, Range: $[1-5$ mV$]$