Let K₁ and K₂ be two strike prices, and K₁ < K₂. C_A(K₁), C_E(K₁), P_A(K₁), and P_E(K₁) are the prices of American and European call and put prices for strike price K₁. Similarly, we have option prices for strike price K₂. Which of the following statements are true?

1. C_A(K₁) - C_A(K₂) > K₂ - K₁
2. P_E(K₂) - P_E(K₁) > K₂ - K₁
3. The graph showing the relationship between strike prices and call and put prices is concave.

a.

i and ii

b.

ii and iii

c.

i and iii

d.

i, ii, and iii are all true

e.

i, ii, and iii are all false