Not quite. The Pentax K camera users have a substantially larger number and variety of lenses than any other mount at their disposable, I think.
Originally Posted by JLP
They can accept the Pentax K-mount lenses, as well as Pentax M42 lenses with an adapter. Plus, there are the almost infinite number of third-party K-mount and M42 lenses going back to the mid-1940s, beginning with the Contax (the original M42 camera) right up to the current offerings from Carl Zeiss in both K and M42. In between are the various offerings from Ricoh, Tokina, Vivitar, Tamron, Sigma, Cosina, Fuji (M42), Mamiya (M42), Yashica (I think they had an M42 camera), Carl Zeiss, Carl Zeiss Jena and the many others that I can't recall at the moment.