The correct answer is C. Unintentional.
Inadvertent means unintentional or accidental. It is often used to describe actions that are done without thinking or planning. For example, you might say that you “inadvertently” spilled your coffee if you accidentally knocked it over.
The other options are incorrect because they do not accurately describe the meaning of the word “inadvertent.”
A. Ignorant means lacking knowledge or awareness. For example, you might say that someone is “ignorant” about a particular topic if they do not know anything about it.
B. Unexpected means not expected or anticipated. For example, you might say that a surprise party is “unexpected” if you did not know that it was going to happen.
D. Undisturbed means not disturbed or troubled. For example, you might say that you are “undisturbed” by the noise if it does not bother you.