What is the meaning of the word contiguous?

The term "contiguous" refers to things that are adjacent or touching each other, without any gaps or interruptions. In geographical or spatial contexts, it often describes areas that are connected or share a common boundary. For example, contiguous states in the United States refer to states that are connected to one another without any breaks—Alaska and Hawaii are not included in the contiguous states.

Understanding that "contiguous" involves proximity helps clarify why this choice is the best fit. The other choices do not accurately capture the essence of the word. "Unique" implies something being one of a kind, while "indirect" suggests a lack of directness or immediacy. "Pleased" relates to a feeling of satisfaction or happiness, which does not connect to the spatial or relational aspect conveyed by "contiguous." Thus, adjacent is the correct choice, as it encapsulates the idea of being next to one another seamlessly.