A patient is observed to have a significantly increased blood clotting time. According to the classification of vitamins and their deficiency diseases, this condition is most likely caused by the deficiency of which of the following vitamins?

Step-by-step solution

According to the NCERT textbook, the deficiency of Vitamin K causes an increased blood clotting time. Vitamin C deficiency causes scurvy (bleeding gums), not an increased clotting time. Vitamin E deficiency leads to increased fragility of RBCs and muscular weakness. Vitamin B₁₂ deficiency causes pernicious anaemia (RBCs deficient in haemoglobin). Answer: Vitamin K