Select all that are true. The program counter:

Choice $1$ of $5$:Counts the number of instructions in the program.

Choice $2$ of $5$:Contains a pointer to the instruction the CPU will execute next.

Choice $3$ of $5$:Can be modified by the interrupt hardware.

Choice $4$ of $5$:Changes as the program executes.

Choice $5$ of $5$:Is stored in the memory system.