Which of the following best indicates why the left ventricular myocardium is thicker than the right ventricular myocardium?

A) Left ventricular oxygen saturation is greater in the left ventricle.
B) The left ventricle works harder than the right ventricle.
C) The aortic valve is narrower than the pulmonic valve.
D) Left ventricular volume is less than right ventricular volume.