$\backslash$table$[[,,$Final,Shadow,Constraint,Allowable,Al$],[$Ce$11,$Name,Value,Price,R$.$H$.$ Side,Increase,Di$],[$$E$$2,$Resource A$,20,7\mathrm{.}78,20,10,],[$$E$$3,$Resource B$,30,6,30,50,],[$$E$$4,$Resource C$,18,0,40,1E+30,]]$

If the coefficient of Activity $1$ in the objective function changes to $$10,$ then:

$$ a$)$ the original solution remains optimal.

b$)$ the problem must be resolved to find the optimal solution.

c$)$ the shadow price is valid.

d$)$ the shadow price is not valid.