Answer:
Holly should buy the half liter.
Explanation:
Holly should buy the half liter because it will cost less. 10^3 mL (1,000 mL) is the same as 4 x 250. If a 250 mL bottle costs $1.43, it will cost $5.72 for one liter and $11.44 for two liters. The half liter however, will only cost $9.80 ($2.45 x 4)