Which of the following options requires the least amount of activation energy during a chemical reaction?

Enzyme Action

O The chemical reaction without enzyme

O The chemical reaction with enzyme

PLEASE HELP FAST

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.

answer///systemic;