The correct option is A Brain
In the normal resting state of humans, most of the blood glucose burnt as 'fuel' is consumed by brain, because, brain also works in resting state of humans, which requires energy. So, brain use blood glucose as fuel. Thus, option A is correct.
In the normal resting state of humans, liver, kidney and adipose tissues also in resting state, so, can not use blood glucose as energy source. Thus, other options are incorrect.