Answer:
Trailing from his aching jaw
Step-by-step explanation:
The option is correct.
This above answer compares the fish to an old, experienced soldier.
From my answer above we can deduce that the word "trailing" has to do with "moving slowly". This can be connected to an old age. Also, it talks about "aching jaw". We can deduce as well that the aching is as a result of age.
Sometimes, old men may experience jaw pain due to advancement in age.