To understand which of the given options can sometimes be zero for a moving body, let's look at each option individually:

i. Average velocity:
Average velocity is defined as the change in position divided by the change in time. It is a vector quantity, which means it has both magnitude and direction. The average velocity can be zero if the displacement of the body is zero over a given time interval. This means that the body is not changing its position and is at rest.

ii. Distance traveled:
Distance traveled is the total length of the path taken by a moving body. It is a scalar quantity, which means it only has magnitude. The distance traveled can never be negative and is always a positive value. Therefore, it cannot be zero for a moving body unless the body does not move at all.

iii. Average speed:
Average speed is defined as the total distance traveled divided by the total time taken. It is a scalar quantity. Average speed can be zero if the total distance traveled by the body is zero over a given time interval. This means that the body does not move at all during that time.

iv. Displacement:
Displacement is the change in position of a moving body and is a vector quantity. It is the shortest distance between the initial and final positions of the body, taking into account the direction. Displacement can be zero if the initial and final positions of the body are the same, indicating that the body has returned to its starting point.

So, from the given options, both average velocity and displacement can sometimes be zero for a moving body. Average velocity can be zero if there is no change in position, and displacement can be zero if the body returns to its starting point. Therefore, the correct answer is option 'C' - (i) and (iv).

In summary, the average velocity and displacement can sometimes be zero for a moving body, while the distance traveled and average speed cannot be zero unless the body does not move at all.