In English mistakes are often made by using the wrong preposition after certain words. This is one example…
Anxious about refers to the subject of worry.
New mothers and fathers are often anxious about their parenting skills.
Anxious for indicates a positive concern or a desire for something.
Entrepreneurs are anxious for cordial relations with emerging Central Asian nations.
Anxious at refers to the cause of worry and anxious to indicates eagerness and is followed by a verb.
The letter carrier became anxious at the sight of the unleashed dog.
The magician was anxious to please her young audience.
Now what you were looking for….
The correct answer was… A