The national institute for niosh defines workplace violence assault, threatening behavior or abuse occuring in the workplace

Be by his side : ) make him feel better

Ibelieve this would be an obstacle.

If it's a smaller child or infant, place one on the middle of the chest and on the child's back. (if it is a bigger child with enough room for two, place one on the upper right/your left of the chest, and one on the lower left/your right) the pads should never touch each other. 

The answer is d. worthless