When food enters the digestive system, it - A) is transferred through the system by the force of gravity pulling the food
B) is transferred through the system by the force of muscles contracting and pushing the food
C) is transferred through the system by the force of muscles relaxing and pulling the food
D) is transferred through the system by the force of muscles relaxing and pushing the
PLSSS HELPPP

i think it's D.

Explanation:

(im not 100% tho)

hope this helps (´▽`ʃ♡ƪ)

answer: the blood-brain barrier is a layer of specialized membranes and cell processes designed to keep undesirable substances from passing from the bloodstream into the precious tissues of the brain. while the blood-brain barrier does keep most bad things out of the central nervous system, it is not impermeable.

explanation:

answer///alimentary canal/gastrointestinal tract.digestive (gi);