D would be correct (i did this Assessment today)<span />
Answer:

Explanation:
Hello,
In this case, a solution is formed when a solute is completely dissolved in a solvent, thus, for this situation, the sugar is the solute and the water the solvent but in addition to them we find spices which are also considered in the total mass of the solution. In such a way, for computing the total mass we must add the mass of three constituents (115 g sugar, 350 g water and 5 g spices) as shown below:

Best regards.
Answer:
Here's what I get
Explanation:
A. Initial observation
Gary's shell had slime and an odour.
B. Independent variable
The independent variable is the one that the experimenter changes.
There are two independent variables: the rubbing with seaweed and the drinking of Dr. Kelp.
C. The dependent variable
The dependent variable is the amount of slime and odour.
D. The conclusion
Sponge Bob can conclude that rubbing the shell with seaweed and drinking Dr. Kelp removes the slime and odour.
However, this was a poorly designed experiment. He doesn't know if it is the seaweed or the Dr. Kelp that gives the result or if he must use both together. He should change only one independent variable at a time.