<prompt>  A patient of rheumatic heart disease with mitral stenosis and atrial fibrillation is on oral warfarin. On one OPD visit, his INR is found to be 6. What is the action to be taken?Stop warfarin, and reviewStop wairfarin, and administer fresh frozen plasmaStop warfarin, and administer intramuscular vitamin KStop warfarin, and administer intramuscular vitamin K 