I believe the possible answer is B
An
incomplete closure of one or more vertebrae, with no protrusion of the
spinal cord or the membranes covering the brain and spinal cord, called
the meninges.<span>
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Atrial fibrillations the problem of irregular heartbeats, due to which clots can form inside the veins, and may lead to stroke, and ultimately, heart failure. An anticoagulant is given to such patients, to decrease the chances of occurrence of a heart attack due to blood clot formation.