Answer:
D. K3PO4
Explanation:
K3PO4 would dissolve into 3 potassium ions and one phosphate ions thus total of 4 items added in water. Freezing point is depressed by high amounts of stuff. NaCl would add 2 items (one Na and one Cl). Glucose would not break apart, thus 1 item. MgCl2 would break into One Mg and two Cl ions (thus 3 things.)..
Overall, K3PO4 dissolves into most components, thus would depress the freezin point most.
