Kuhlau-Check Up "2-dan" (Answer-16, Question-17)

Answer No.16 You are correct.

Kuhlau met Beethoven on September 2, 1825. He had stopped at Vienna during his two years' intended abroad travel. At that time, Beethoven was ill-conditioned\ and had lived in Baden, the suburb of Vienna. Kuhlau visited him there.
Beethoven's portrait given to him is stored in the Music History Museum of Copenhagen.

Question No.17

Kuhlau's Opus Number is from 1 to 127. Is there any number out of use in those?