Questions are referring to commands in a Linux Virtual Machine terminal

1) (Pipelines and I/O redirection) What do the following commands do? Describe their behavior.

a. date > foo ; echo "" >> foo ; cat /tmp/bigfile.txt | sort | uniq >> foo

b. tr a-z A-Z < foo > bar

c. When the previous command was run, what was the value of argc?

Please answer question c!!