Concept:Adjectives that are not coordinate—like "beautiful" and "European"—do not need a comma between them.
Explanation:Coordinate adjectives can be separated by "and" and appear in any order.
Here, "beautiful" describes the overall impression, while "European" tells the origin.
They cannot be swapped ("European beautiful woman" sounds unnatural) and "beautiful and European" is not natural.
Thus, they are cumulative adjectives and should not be separated by a comma.
Option C correctly has no comma. Option A wrongly inserts a comma after "beautiful".
Option B puts a comma after "met", breaking the subject-verb flow.
Option D puts a comma after "European", which is incorrect.
Only Option C uses proper punctuation.
Answer:C. I met a beautiful European woman.