Byte pair encoding is a data encoding technique. The encoding algorithm looks for pairs of characters that appear in the string more than once and replaces each instance of that pair with a corresponding character that does not appear in the string. The algorithm saves a list containing the mapping of character pairs to their corresponding replacement characters. For example, the string "THIS_IS_THE_BEST_WISH" can be encoded as "%#_#_%E_BEST_W#H" by replacing all instances of "TH" with "%" and replacing all instances of "IS" with "#".
Which of the following statements about byte pair encoding is true?
A. Byte pair encoding is an example of a lossy transformation because it discards some of the data in the original string.
B. Byte pair encoding is an example of a lossy transformation because some pairs of characters are replaced by a single character.
C. Byte pair encoding is an example of a lossless transformation because an encoded string can be restored to its original version.
D. Byte pair encoding is an example of a lossless transformation because it can be used to transmit messages securely.