Critical Reasoning (CR) | Although many brands of gasoline are sold on Haibei Island, gasoline c

Although many brands of gasoline are sold on Haibei Island, gasoline companies there get all of the refined gasoline they sell from Haibei seaport's only storage tank, which is always refilled with the same quality of gasoline. Therefore, the brands of gasoline of sale on Haibei may be different in name and price, but they are identical in quality.

The conclusion drawn above depends on which of the following assumptions?

(A) Consumers are usually unaware of variations in the quality of the gasoline
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