Let $S = \{(x, y) : x^2 + y^2 - 25 = 0$ and $x \geq 0\}$. Consider the statements:

1. The relation is not a function.
2. The graph of the relation is a half-circle.
3. The graph lies on the upper half plane of the x-axis.

• ai and ii
• bi and iii
• cii and iii
• di, ii and iii