Final answer:
An isotonic solution has the same osmolarity as body fluids.
Step-by-step explanation:
An isotonic solution is one that has the same osmolarity as body fluids.
Osmolarity refers to the concentration of solute particles in a solution. In this case, the solution's concentration is measured in mOsm (milliosmoles).
To determine if a solution is isotonic, we compare its osmolarity to the osmolarity of body fluids. If the solution's osmolarity is similar to that of body fluids, it is considered isotonic.
Out of the given options, the only one that corresponds to an isotonic solution is (b) 350 mOsm.