Answer:
In sentence D, change "it" to "the bridge."
Step-by-step explanation:
In the sentence D, ''it'' should be changed to ''to bridge'' because of the previous sentence in which he said that his brothers had caught an extremly big fish. Because of the previous sentence, he should change it to ''the bridge'' because the readers can think that they have stayed on the big fish that they caught which would be absurd, and in that way, this paragraph would make no sense.
The other usage of ''They'' and ''My brothers'' is good because it is balanced in the paragraph. In every second sentence he is using ''They'' and after that ''My brothers'' so the readers have a good perception of his thoughts.