Respuesta :
The speaker means that B. Even when they were tired and had doubts, they remained faithful.
The "voices singing in [their] ears" were themselves, thinking of the doubts they have.
The "voices singing in [their] ears" were themselves, thinking of the doubts they have.
B is your answer because folly means foolish, so they probably felt like the journey was almost pointless. But they continued to travel because they had hope that the many miles they had traveled were worth it.