On a lab bench, there are four balloons filled with identical volumes of different salt solutions: 0% (balloon A), 5% (balloon B), 10% (balloon C), and 15% (balloon D). There are also four beakers each filled with identical volumes of a 10% salt solution. The balloons are semi-permeable; that is, only water can enter and exit the balloon. All four balloons are placed in separate beakers at the same time and are allowed to come to equilibrium. Which is the correct order of balloon volumes at equilibrium, from largest to smallest

Explanation:

The correct order of balloon volumes at equilibrium, from largest to smallest:

Balloon D  > Balloon C > Balloon B > Balloon A.

Osmosis is defined as the process of  movement of water molecules from the region of their higher concentration to the region of their lower concentration i.e. from a less concentrated concentrated solution to a solution with greater concentration through a semipermeable membrane.

So , In case of balloon A and B water will move out of them and at equilibrium it will have reduced volumes. However, A will lose more water that B.

In case of Balloon C no water movement will be observed it will remain constant.

In case of Balloon D, Water will move inside the balloon and its volume will increase.

Thus at equilibrium the  order of balloon volumes will be :

Balloon D  > Balloon C > Balloon B > Balloon A.

i think its both a and b