Consider the following statements about orthogonal projection: Which of the following is correct?

1. The foot of the perpendicular drawn from any point on any line is the orthogonal projection of that point.
2. The orthogonal projection of a line perpendicular to another line is a point of zero length.
3. A line segment parallel to a definite line is equal in length to its orthogonal projection on that line.

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