Final answer:
To make a small amount of solution more concentrated, an Evaporating dish is used to remove solvent by evaporation, increasing the solute concentration.
Step-by-step explanation:
The best choice of lab equipment to make a small amount of solution more concentrated is D. Evaporating dish. Concentrating solutions involves the removal of solvent, typically by evaporation or boiling, as long as the process does not affect the solute itself. An evaporating dish is specifically designed for gently heating a solution to accelerate the evaporation of the solvent, which increases the concentration of the solute within the remaining solution.