What component are inside a CPU?

The central processing unit $($CPU$)$ has two components: Control Unit and the arithmetic logic unit $($ALU$)$

The central processing unit $($CPU$)$ has two components: The memory and the arithmetic logic unit $($ALU$)$

The central processing unit $($CPU$)$ has only one component: The memory.

The central processing unit $($CPU$)$ has three components: the buses, the memory, and the input$/$output unit.