Critics of Unilever$$s Sustainable Living Plan questioned $\_\_\_\_\_\_\_\_\_\_\_.$

Select answer from the options below

a$.$ whether Unilever has the power to affect its customers$$ behavior

b$.$ whether Unilever can be financially successful while following sustainable practice

c$.$ whether Unilever can reduce its environmental impact by one$-$half over the next $10$ years

d$.$ Both a and b