Here is the table $($including Supply Demand$)$ for a transportation LP

$\backslash$table$[[$Name$,$D $1,$D $2,$D $3,$D $4,$Supply$],[15,8,4,3,12],[$S $2,11,9,11,4,13],[$S $3,2,15,13,5,10],[$Demand$,9,7,13,6,],[,,,,,]]$

Perform Vogel's method and answer the following:

The first B variable ij position is

$$

The second B variable ij position is

The starting value of w upon completion of Vogel assignment is $$

Is this initial tableau optimal? Y$/$N

$$