Question

1. one of the earliest observation studies from the 18th century was the relationship between

omega 3 fatty acids and heart disease
vitamin c and scurvy
calcium and osteoporosis
sunlight and skin cancer

Explanation:

In the 18th - century, sailors were known to develop scurvy, and it was observed that vitamin - C rich foods could prevent it. The relationship between vitamin C and scurvy was one of the early observational studies. Omega - 3 fatty acids and heart disease research is more modern. Calcium and osteoporosis research also developed later. The link between sunlight and skin cancer is a more contemporary discovery.

Answer:

Vitamin C and scurvy