The correct answer is A. On the other hand
Step-by-step explanation:
In a text or speech with a compare and contrast organizational pattern the focus is to state and analyze the differences and similarities between two subjects; for example, tow educational programs or two types of vehicles. Due to this, in this pattern, it is common to use transitional words or phrases that show similarities such as similarly, like or equally, and transitional words or phrases that show contrast this includes on the contrary, on the other hand, unlike or however.
According to this, the transitional phrase that is commonly used in the compare and contrast organizational pattern is "on the other hand" as this can be used to show contrast or differences between the two subjects discussed in a text or speech that is necessary when using this pattern.