Which of the following has a knot of nerve tissue at its head end?

On one hand, i aspire to an ivy league vocation: 1 professor of the sciences in higher education. 2 but like noble amphibians that thrive on land and in the stream, 3 i've got another world of which i like to gladly dream. 4 some say that it's abnormal; my affections are exclusive. 5 in science, they say, emotions are something quite elusive. 6 line 3 exemplifies which kind of figurative language? a) hyperbole b) metaphor c) onomatopoeia d) simile