help me with a SAT grammar question?! Please!!

Test Preparation
1

<p>Smallest of the copperhead snakes, the broad-banded copperhead, if disturbed, vibrates its tail (rapidly, and is also known to secrete a ) substance that smells like cucumbers.</p>

<p>Above is the answer but I feel like the other option may well sound just right.
rapidly, in addition, it secretes its
To be honest, both seem awkward to me, so anyone help me why one is right and the other is wrong grammatically? Thank you all so much!!!</p>

2

<p>“And” is a FANBOYS (coordinating conjunction). “In addition to” is a conjunctive adverb phrase. The former can be used to join independent clauses with a comma; however, the latter requires a semicolon. (See what I did there?)</p>