<span>D. But we had not traveled fifty miles down the stream before we found the water gradually becoming brackish and discolored from the salt and</span>
I don't get it either maybe try google just trying to help
The correct answer is B. "The Wind Gives Life"
That answer fits best the excerpt that you didn't provide, but was quite common among students who asked the same question.
A dangling modifier is a type of a modifier which is placed incorrectly or the noun it is supposed to modify isn't clearly stated in the sentence.
Having this in mind, the sentence which contains a dangling modifier is <span>A. Playing with the children, it was obvious they had a good time.
It should be rewritten somehow to say: It was obvious they had a good time playing with the children. </span>