If the equation, x² - ax + 1 = 0 has two distinct and real roots, then:

1. |a| ≥ 2

2. |a| ≤ 2

3. |a| > 2

4. |a| < 2

The positive value of k for which the equations x² + kx + 64 = 0 and x² - 8x + k = 0 will both have real roots, is

1. 16

2. 8

3. 12

4. 4