Told can indeed be a participle or a verb, depending on the context.
Here it's verb: it's a past tense of "tell".
It could be a participle if the sentence were as follows:
I puffed by cheeks to get rid of the hiccups, told by my cousin to do so. (it's a weird formulation but not incorrect I believe)
<span />
C. because his mother was dead
Personification because it's saying the river knows as if it is a person or higher being.
