The command to count the number of files in the current directory by using pipes, is A. ls | wc B. ls -l | wc -l C. ls | wc -w D. ls | ws -c E. None of the above

The correct answer is A. ls | wc.

The ls command lists the files in the current directory. The wc command counts the number of lines, words, and characters in its input. When we pipe the output of ls to wc, wc will count the number of files in the current directory.

The ls -l command lists the files in the current directory in long format. The wc -l command counts the number of lines in its input. When we pipe the output of ls -l to wc -l, wc will count the number of lines in the files in the current directory.

The ls | wc -w command counts the number of words in the output of ls. This is not what we want, because we want to count the number of files, not the number of words in the file names.

The ls | ws -c command counts the number of characters in the output of ls. This is also not what we want, because we want to count the number of files, not the number of characters in the file names.

Therefore, the correct answer is A. ls | wc.