Its spindle-shaped cells allow it to do smooth movements which is how the structure of the cardiac muscle helps it to perform its functions.
This is also referred to as the myocardium and is the thick middle layer present in the region.
It resists fatigue and contracts in a coordinated manner through spindle-shaped cells thereby ensuring that the smooth movement allows blood to be pumped to other parts of the body. This is the reason why option A was chosen as the most appropriate choice.
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