Concept:This question tests the correct preposition used in the fixed comparison pattern "prefer
X ___
Y".
Explanation:The verb "prefer" already expresses a comparison, so it requires the preposition "to".
The correct structure is "prefer
X to
Y".
For example, "I prefer tea to coffee" means I like tea more than coffee.
The word "than" is used with comparative adjectives like "better", not with "prefer".
The options "from" and "over" are not idiomatically linked with "prefer" in this construction.
Therefore, the sentence is best completed by "to".
Answer:A. to