Refer to the following sensitivity report for a maximization problem and answer the questions below:$$ADJUSTABLE CELLS

$.$Cell

Final Name Value

Number of Tables $30$

Objective Allowable Coefficient Increase

$51$E $+30$

$46$

Allowable Decrease $.3$

$1$E $+30$$B$$9$ $C$$9$

Number of Chairs $0----------------------------------------------------------------------------------------------------------------------------------------------------------.$CONSTRAINTS

Final Cell Name Value

$.$a$.$ b$.$ c$.$ d$.$ e$.$

$60<=$RHS$<=120120<=$RHS$<=800<=$RHS$<=8060<=$RHS$<=20$

none of the above

Shadow Price

$0$

Constraint R$.$ H$.$ S$.$

Allowable Increase $1$E $+30$

Allowable Decrease $30$

$..$$D$$6$ Assembly $90$

$D$$7$ Painting $602\mathrm{.}5602060$

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$1$ What is the optimal value of the objective function? a$.30.$

b$.90.$ c$.60.$ d$.150.$ e$.120.$