Answer:
The correct answer is a. scurvy
Explanation:
Scurvy is a deficiency disease which is caused by the deficiency of vitamin C. James Lind in the 18th century discovered that citrus fruit prevents scurvy and can help in curing the scurvy. Scurvy was the main cause of death in sailors during long-distance sea travells.
Citrus fruits have plenty of vitamin C which is required for in variety of biosynthetic pathway and lack of vitamin-C cause weakness, gum disease, anemia, and skin problems. So eating citrus fruits prevents scurvy.