At the end of ventricular diastole -a) Atrial volume is moreb) Coronary flow is maximumc) Flow in aorta dropsd) All of the above
Cardiac cycle 

By convention, the mechanical cycle is considered to begin at ventricular end diastole, the instant just before systole, when the ventricle begins to actively generate tension as signalled by a sudden rapid rise in intraventricular pressure.
Soon after the ventricular systolic pressure begins to rise, it exceeds atrial pressure, the time when A. V (mitral and Tricuspid) "close producing S1”
Ventricular pressure then continues to rise rapidly until Aortic and pulmonary artery pressures are exceeded, resulting in the opening of the Aortic and pulmonary valve and the onset of a period of ejection of blood into the systemic and pulmonary circulation.
Note, in the phase between A.V valve closure and Aortic pulmonary valve opening, the ventricular volume is constant. This phase of the cycle is termed isovolumetric contraction.
As the ejection proceeds, ventricular and AO/PA rise and then fall together. When ventricular pressure falls below Aortic pressure the Aortic and pulmonary valve close and ejection end. The closure of Aortic and pulmonary valve produce the "second heart sound".
The left ventricle continues to relax and its pressure falls rapidly until it drops below left atrial pressure when the mitral valve opens. Since Aortic and mitral valve was closed during this period, the ventricular volume is constant - this is called "isovolumetric relaxation".
The time when ventricular pressure falls below atrial pressure signals the onset of the ventricular filling period i.e. immediately after the A. V valve opens, there is a rapid inflow of blood into the ventricles (rapid filling phase).
This occurs due to A.V pressure gradient. This phase is characterized by (y wave) of the .I. VP
Following the rapid filling phase, the A. V gradient diminishes markedly the filling slows and actually may come to a halt. This period when blood trickless down in ventricle is called diastasis.
The slow filling is immediately followed by the final filling event contraction of atria; which results in a second
increase in the A.V gradient and injection of an additional bolus of blood into the ventricle. (`a' wave of the JVP.)

Coming back to the question
Option 'a'

At the end of ventricular diastole, the atria is almost empty pouring all its blood into the ventricle.

Option 'c'

During the ventricular diastole, the aortic valve is closed so naturally the Aortic flow is decreased.

Option 'b'

"Phasic changes in coronary blood flow"
The blood flow in the coronary artery falls during systole. The reason for this is the strong compression of the left ventricular muscle around the intramuscular vessels during systole.
Note that it is opposite to other vessels of the body where blood flow increases during systole.
During diastole, the cardiac muscle relaxes and no longer obstructs the blood flow through the left ventricular muscle capillaries, so that blood flows rapidly increases during all of diastole.
a
bc
ac
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