B. Activation
During translation, tRNA molecules are charged or activated with a specific amino acid that corresponds to their anticodon sequence. This activation process is catalyzed by aminoacyl-tRNA synthetases, enzymes that recognize specific tRNA molecules and attach the appropriate amino acid to their 3' end. The charged tRNA is then able to participate in the elongation step of translation, where it delivers its amino acid to the growing polypeptide chain. Therefore, the step of translation in which the tRNA becomes charged is called activation.