Which of the following, if true, most seriously weakens the support the example lends to the executive's contention that music publishers have been devastated by the photocopier? A. Only a third of the 1,200 singers were involved in performing the music published by the executive's company. B. Half of the singers at the festival had already heard the music they were to perform before they began to practice for the festival. C. Because of shortages in funding, the organizing committee of the choral festival required singers to purchase their own copies of the music performed at the festival. D. Each copy of music that was performed at the festival was shared by two singers. E. As a result of publicity generated by its performance at the festival, the type of music performed at the festival became more widely known.