Answer:
Phenylalanine.
Explanation:
The A site (aminoacyl) is the first binding site in the ribosome. In this case, in the exit site is GAC (Asparagine), next to it is CAU, for the Histidine referred in the question as reference, and then, in the A site you find UUU, that according to the genetic code translates in phenylalanine.