4. The optimal BFS of the following LP maxr1+2r2+r3+3r4+2rE+r0 x4+3xn=6 I1,T2,T3,T4,T6+T20 is In=I3I4x5=614,IN=I1I2IE=000 Consider the following perturbed LP (a) For what range of is BV={x3,x4,r5},NBV={x1,x2,xA} still a BFS? (b) For what range of is BV={I3,T4,T5},NBV={I1,I2,I8} still an optimal BFS? 4. The optimal BFS of the following LP maxr1+2r2+r3+3r4+2rE+r0 x4+3xn=6 I1,T2,T3,T4,T6+T20 is In=I3I4x5=614,IN=I1I2IE=000 Consider the following perturbed LP (a) For what range of is BV={x3,x4,r5},NBV={x1,x2,xA} still a BFS? (b) For what range of is BV={I3,T4,T5},NBV={I1,I2,I8} still an optimal BFS