Consider the following statements regarding a path line in fluid flow:
1. A path line is a line traced by a single particle over a time interval.
2. A path line shows the positions of the same particle at successive time instants.
3. A path line shows the instantaneous positions of a number of particles, passing through a common point, at some previous time instants.
Which of the statements given above are correct?
a. Only 1 and 3
b. Only 1 and 2
c. Only 2 and 3
d. 1, 2 and 3