Which statement accurately contrasts type 1 and type 2 diabetes?

• A. Type 1 is autoimmune destruction of beta cells leading to insulin deficiency; Type 2 is insulin resistance with progressive beta-cell dysfunction.
• B. Type 1 is caused by obesity; Type 2 is purely genetic.
• C. Type 1 can be managed without insulin in all cases.
• D. Type 1 and Type 2 are identical except for age of onset.

Answer: (A)

The main idea is how insulin action goes wrong in each type. Type 1 diabetes is an autoimmune attack on the pancreatic beta cells, leading to little or no insulin production (absolute insulin deficiency). Type 2 starts with the body’s tissues becoming resistant to insulin, and over time the pancreas can’t keep up, resulting in progressive beta-cell dysfunction and reduced insulin production. This distinction is why the statement that Type 1 involves autoimmune beta-cell destruction causing insulin deficiency, while Type 2 involves insulin resistance with progressive beta-cell dysfunction, is the best contrast.

In Type 1, without insulin, glucose stays outside cells, causing high blood sugar, and people typically need insulin therapy from diagnosis. In Type 2, initial management focuses on improving insulin sensitivity and reducing glucose production, with lifestyle changes and various medications; insulin may be needed later as beta-cell function declines. The other options misstate origins or treatments (Type 1 isn’t caused by obesity, Type 2 isn’t purely genetic, Type 1 isn’t always insulin-free, and the diseases aren’t identical aside from age).