About single$-$cycle and malti$-$cycle implementation of CPU in comguter organization, which of the following statements are NOT tnue?

$($A$)$ Single$-$cycle implementation of CPU is not used in the mainstrenm processors nowadays.

$($B$)$ For single$-$cycle implementation of CPU, the clock cycle is determined by the shortest possible path.

$1$C$)$ Single$-$cycle implementation of CPU allow's a functional unit to be used more than once per instruction.

$($t$)$ Compared to single$-$cycle implementation, multicycle implementation is more efficient.

Multicycle implementation is more suitable for pipeline impiementation.