The correct nomenclature for the following compound is:
\( 2 \)-formyl-\( 4 \)-hydroxyhept-\( 6 \)-enoic acid
\( 2 \)-carboxy-\( 4 \)-hydroxyhept-\( 6 \)-enal
\( 2 \)-carboxy-\( 4 \)-hydroxyhept-\( 7 \)-enal
\( 2 \)-formyl-\( 4 \)-hydroxyhept-\( 7 \)-enoic acid