(b).

LA passive volumes
(i) Preatrial contraction volume (V preA), measured at the onset of the P-wave using an electrocardiogram (ECG).
(ii) Minimal LA volume (V min⁡), measured at the closure of the mitral valve and end-diastole.
(iii) Maximal LA volume (V max⁡), measured just before the opening of the mitral valve in end-systole.
LA active volumes
(i) LA reservoir volume (V max⁡ − V min⁡)
(ii) LA conduit volume (LV total stroke volume − LA reservoir volume)
(iii) LA passive emptying volume (V max⁡ − V preA)
(iv) LA contractile volume (V preA − V min⁡)