The correct answer is D. Alone.
Explanation:
In language, words are usually composed of root words, suffixes and prefixes, root words refer to the basic units of words, while suffixes and prefixes are syllables or letters added at the end of a rood word in case of suffixes, for example, "-ing", "-ation" or "-itis"; or placed in the beginning of a word in the case of prefixes, for example, "un-", "pre-" or "re-". Both prefixes and suffixes provide information and meaning to the root word. In the case of the word "solitaire", the root is "sol-" which means alone and the suffix is "-aire" means a person that is characterized, which means solitaire refers to a person that is mainly alone. Also, the root word "sol" derives into other words such as "solitude" or "solo" whose meaning is linked to the word alone. So, the correct answer is D. Alone
