Which character should be placed before the pattern 'pat' in the grep command to find matches only at the start of a line?

Explanation

In grep, the caret symbol (^) is used to anchor the pattern to the beginning of a line. Therefore, '^pat' matches 'pat' only if it appears at the start. The dollar sign ($) anchors to the end of a line, so '$pat' and 'pat$' are incorrect, and 'pat^' is not a valid syntax.