What holds the log of Active Directory transactions or changes?

What is the result of the following command sequences?

ls | wc -l rm ??? who | wc -l mv progs/* /users/steve/backup ls *.c | wc -l rm *.o who | sort cd; pwd cp memo1 .. plotdata 2>errors &

In PHP, which bitwise operation is signified by the pipe (|) character?

In PHP, which bit wise operation is signified by the pipe (|) character? a. OR b. XOR c. AND d. NOT