You are given a line balancing problem with the following data $($A$,-,5),(B,A,5,($D$,$ B and $C,6,7),$ where the first letter is the task, second is the order of precedence, third is process time.

Q: Using ranked positional weight heuristic calculate the number of workstations for the desired cycle time $C{T}_d=11$ and the line efficiency based on this heuristic.

$4,0\mathrm{.}727$

$3,0\mathrm{.}97$

$3,0\mathrm{.}89$

$4,0\mathrm{.}80$