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

1. an epidemiological study is a type of clinical trial.

○ true
○ false

1. epidemiological studies link cause and effect.

○ true
○ false

Explanation:

Question 3

In the 18th century, the relationship between Vitamin C and scurvy was studied (sailors with lack of fresh fruit - Vitamin C - got scurvy). Omega 3 and heart disease, calcium and osteoporosis, sunlight and skin cancer studies were later.

Epidemiological studies observe populations (e.g., disease prevalence), while clinical trials test interventions (e.g., drug efficacy) on participants. So epidemiological study is not a clinical trial.

Epidemiological studies (like cohort, case - control) analyze associations to infer cause - effect (e.g., smoking and lung cancer link from epidemiology).

Answer:

B. Vitamin C and scurvy

Question 4