40 One of the reasons why casting a play is no easy task is that people who show up for tryouts mumble or speak ininaudible whispers.
(A) The only reason why casting a play is not easy is that people coming for tryouts would mumble or speak ininaudible whispers.
(B) Casting a play is quite difficult. For one thing, people who come to auditions are often inarticulate.
(C) Casting a play is not a hard task because lots of people who show up for tryouts speak loudly.
(D) Watching a play is hard because the audience that show up mumble or speak in inaudible whispers.