In a ribosome there are 3 tRNA sites (P, A and E).
The P site, also called the peptidyl site, binds to the tRNA holding the growing polypeptide chain of amino acids. THIS IS YOUR ANSWER!...P or peptidyl
The A site (acceptor site) binds the aminoacyl tRNA which brings the new amino acid that will be added to the polypeptide chain.
The E site (exit site) serves as the exit and is where the tRNA that has now lost its amino acid lets go of the ribosome.