I think it's C. Heavy means the sigh was long, and obviously loud. Wind through a tomb is used as a metaphor that the sigh was lonely. Lonely means nobody is there, and nobody is there to hear wind go though a tomb, and anyone in the tomb can't hear, because, well, they're dead.
A hero is a savior figure, he stands up to injustices of people through acts of bravery and courage. He stands up against all odds for a specific cause. A King merely rules through ascension to the throne. Beowulf not only rids the Danes of Grendel, but also his mother and the dragon.
