What was one of the main reasons for the failure of the Beer Hall Putsch?

The failure of the Beer Hall Putsch can be largely attributed to Hitler being arrested and lacking sufficient support at a crucial moment. The Putsch, which occurred in November 1923, was an attempt by Hitler and the Nazi Party to overthrow the Weimar government in Munich. Initially, there was some level of enthusiasm and support among certain nationalist factions, but as the situation escalated, it became clear that the planned uprising did not gain widespread backing from the military or key political figures.

When the Putsch was confronted by the police and the Bavarian government, the lack of adequate support became evident. Hitler's arrest soon followed, which effectively crippled the movement, and he could not rally further support during its critical moments. This arrest meant that the Nazi Party's leadership was disrupted and their ability to continue the uprising was severely hampered.

The other options do touch on factors related to the coup, but they do not capture the immediacy of the situation during the Putsch itself as B does, which highlights the significance of Hitler's arrest and lack of support at that pivotal point.