Concept:Swollen, bleeding gums are a classic sign of scurvy, which results from a deficiency of vitamin C.
Explanation:Vitamin C is essential for producing collagen.
Collagen keeps the gums, skin, and blood vessels strong and healthy.
When vitamin C is severely lacking, the body cannot maintain connective tissue properly.
This leads to scurvy, with symptoms such as gingivitis, bleeding gums, delayed wound healing, and weakness.
Vitamin K is involved in blood clotting and does not cause gum bleeding when deficient.
Vitamin B mainly supports nerve function and red blood cell production.
Vitamin D helps regulate calcium and phosphorus for bone health.
Therefore, swollen, bleeding gums point directly to a shortage of vitamin C.
Answer:C. Vitamin C