What is the function of the following UNIX command? wc -l <a >b &

1. AIt runs the word count program to count the number of lines in its input, a, writing the result to b, as a foreground process.
2. BIt runs the word count program to count the number of lines in its input, a, writing the result to b, but does it in the background.
3. CIt counts the errors during the execution of a process, a, and puts the result in process b.
4. DIt copies the 'l' numbers of lines of program from file, a, and stores in file b.