Final answer:
The phrase uses a simile to compare the nostrils to pipes, thereby making option (a) Simile the correct answer.
Step-by-step explanation:
The phrase "Like pipes his nostrils jetted crimson runnels" is using a simile as a literary device. A simile is an indirect comparison of unlike things using the words 'like' or 'as'.
In this case, the comparison is made using the word 'like' to compare the nostrils to pipes, therefore, the correct answer to the question is (a) Simile.