Final answer:
The 68-year-old man with bleeding gums, partial edentulousness, red and swollen gingiva, petechiae and larger bruises on the forearms, and low levels of vitamin C in the blood is diagnosed with scurvy. Scurvy is a condition caused by a vitamin C deficiency, resulting in various symptoms such as bleeding gums, hair and tooth loss, joint pain and swelling, and delayed wound healing.
Step-by-step explanation:
The diagnosis for the 68-year-old man with bleeding gums, partial edentulousness, red and swollen gingiva, petechiae and larger bruises on the forearms, and low levels of vitamin C in the blood is c. Scurvy. Scurvy is a condition caused by a vitamin C deficiency, which results in bleeding gums, hair and tooth loss, joint pain and swelling, and delayed wound healing.