The gene sequence

In PCR, when the gene sequence is not known but its protein sequence is. then:
(A) The DNA sequence cannot be amplified at all.
(B) The DNA sequence can be amplified by using two oligopeptides.
(C) The DNA sequence can be amplified by using two degenerate oligonucleotides.
(D) The protein sequence can be amplified using two degenerate oligopeptides.