Can we draw the following hypothesis from the context (see options)? 

Context:

Johann Kastenberger (born October 1, 1958, in Sankt Leonhard am Forst, died November 15, 1988, in Sankt Pölten, Lower Austria) was an Austrian marathon runner, bank robber and murderer. He infamously committed his crimes while wearing a Ronald Reagan mask, earning him the nickname "Shotgun Ronnie". Kastenberger's criminal life was the basis for the 2010 film "The Robber".

Hypothesis: Kastenberger always wore a mask when he committed his robberies. 
Choices: a). Yes. b). It's impossible to say. c). No.
b).