Final answer:
The box of tangerines that a man is carrying as he turns a corner is accelerating, while the box of cereal on a conveyor belt and the box of jewelry in a girl's lap are not accelerating.
Step-by-step explanation:
From the given options, the box of cereal that is moving along a straight conveyor belt at a steady speed and the box of jewelry that a girl is holding still in her lap are not accelerating. These objects are either moving at a constant speed or completely still, so their acceleration is zero.
The box of tangerines that a man is carrying as he turns a corner is accelerating. When the man turns a corner, the tangerines experience a change in their velocity, indicating an acceleration.