a$)-$ b$)|$c$)$d$)!18.$ Which of the following command is used to sort the lines of data in a file in alphabetical order?a$)$ Sortb$)$ Shc$)$ St d$)$ Sort $-$r$19.$ Which of the following is used to represent the top$-$level directory?a$)^$ b$)/$c$)$ Sd$)$@