Calsequestrin in cardiac muscle:

A)Acts as a high-affinity Ca⁺⁺ buffer in the cytosol.
B)Acts as a low-affinity Ca⁺⁺ buffer in the SR lumen,near the ryanodine receptor.
C)Promotes Ca⁺⁺ accumulation by the mitochondria.
D)Increases the Ca⁺⁺ affinity of the sarcolemmal Ca⁺⁺ pump.
E)Facilitates myosin binding to the actin thin filament.