In the video, in the experiment on mental agility after tasting (but not swallowing) sweet liquids, the reporter got the highest score after tasting glucose. according to the reporter, what does the boost in mood and brainpower from tasting glucose illustrate?

The correct answer is that we will continue to seek foods high in glucose.  

The brain is one of the most energetic organs in the body. Although it holds for only two percent of the weight of the body, it utilizes between 20 to 30 percent of the energy of the body. Despite the need for high energy, the brain stores only a small concentration of glucose and requires the bloodstream to deliver a continuous supply.  

the major parts of the digestive system:

salivary glands.

pharynx.

esophagus.

stomach.

small intestine.

large intestine.

rectum.

accessory digestive organs: liver, gallbladder, pancreas.