Answer:
adj. used or understood by all
Explanation:
Universal means it is used or understood by all, meaning this keyboard can be used with any system. This fits the description that it works with every computer in the house.
"present everywhere" would not be correct, it is not present everywhere as a keyboard.
"of or pertaining to all nature" is also incorrect, word choice needs to be specific, we aren't talking about nature.
"found in all languages" is incorrect, even though it is understood by all computers, we aren't talking about languages.
