Final answer:
The indication of improvement for a child with fluid volume deficit is a capillary refill time of less than 2 seconds, which suggests better hydration and circulation.
Step-by-step explanation:
An improvement in a child with fluid volume deficit can be indicated by signs that demonstrate better hydration and renal function. The presence of tears would suggest normal hydration, but in this case, it is not listed as an option. If the urine specific gravity is at a normal range (typically 1.015 - 1.025), it suggests the kidneys are capable of concentrating urine properly. A specific gravity of 1.030, as mentioned in the question, indicates the urine is quite concentrated, which can occur in cases of dehydration; however, an improving trend would be a decreasing specific gravity closer to normal as the child rehydrates. Urine output of <1 ml/kg/hr might be concerning because it is low and could indicate oliguria. An ideal improvement sign would be urine output that is at least 1 ml/kg/hr or higher. Among the options given, a capillary refill time of less than 2 seconds is a great indicator of improvement. It suggests better blood flow and hydration, as prolonged capillary refill time can be a sign of dehydration and shock.