Achemical substance can travel from lungs to the brain in . five to eight seconds b. about a minute and a half c. about the same time as when injected sub-q d. one-half second or less

Five to eight second.

Explanation:

The living organisms are made of the chemical. The hormone, receptors and any information that travels in the body are mainly depends on the chemical substances present in the body.

Chemical substance needs to be travel in the body whenever its require. The speed of the chemical substance depends upon its nature whether the substance is polar or non polar and at the site in which the substance is released. The chemical that travels from the lungs to the brain can travel maximum into 5 to 8 seconds.

Thus, the correct answer is option (a).