In which situation would the stroke volume be the greatest? when venous return is increased when venous return is decreased when the force of contraction is decreased when the difference between edv and esv is small when calcium channel blockers are present?

The correct answer is "when venous return is increased".

This is because when the venous return from the pulmonary veins to the left atrium and subsequently the left ventricle, there will be an increase in the left ventricular filling pressure and volume or the preload which in turn will result to increased left ventricular stroke volume.

The other choices will cause a decrease in stroke volume.

B.) nitrogen fixationnitrogen fixation is the process of nitrogen molecules seeping into the soil and inside plant roots and bacteria. it gives more "life" to plants