Final answer:
Dispensing the liquid when it's time to mix the cement will minimize water loss from evaporation when working with dental cements.
Step-by-step explanation:
The correct answer is c. Dispense liquid when it's time to mix the cement. When working with dental cements, it is important to minimize the loss of water from evaporation. By dispensing the liquid when it's time to mix the cement, you can minimize the exposure of the liquid to the air, reducing the chances of evaporation. This helps maintain the desired consistency and properties of the cement.
Option a. B, C, and D is incorrect because it does not provide specific actions to minimize water loss from evaporation. Option b. Dispensing the powder and then the liquid when ready to mix is not the best approach as it exposes the liquid to the air for a longer period, increasing the chances of evaporation. Option d. Keeping the lid on the liquid is a good practice, but it alone does not ensure minimal water loss.