Love in the Ring (German:Liebe im Ring) is a 1930 German sports film directed by Reinhold Schünzel and starring Max Schmeling, Renate Müller and Olga Tschechowa. Schmeling was a leading German boxer of the 1930s, and the film attempted to capitalise on this. Schmeling later appeared in another boxing-themed film in "Knockout" (1935).

Based on that paragraph can we conclude that this sentence is true?
These were the only two boxing films Max Schmeling ever appeared in

Options:
a). Yes;
b). It's impossible to say;
c). No;
b).