Which of the following commands will find the string foo in the file file1.txt, regardless of foo being in upper or lower case letters?
A.
grep -i foo | file1.txt
B.
grep -n filel.txt < foo
C.
grep -n foo file1.txt
D.
cat file1.txt > grep -n foo
E.
cat filel.txt | grep -i foo
Explanation:
-i ignore case