Study the activity list and its network diagram. Identify the critical path$($s$).$

a$.$ A$-$B$-$G$-$H; A$-$B$-$F$-$K

b$.$ A$-$B$-$G$-$H

c$.$ A$-$B$-$C$-$I$-$L

d$.$ A$-$B$-$G$-$H;A$-$B$-$G$-$J$-$L; A$-$B$-$F$-$K