Which of the Following Statements Describe a Probe as Used

Which of the following statements describe a probe as used in molecular diagnostics?

A) A single-stranded segment of nucleic acid (either DNA or RNA) whose nucleotide sequence is complementary to a target sequence (either DNA or RNA) .
B) A double-stranded segment of nucleic acid (either DNA or RNA) whose nucleotide sequence is complementary to a target sequence (either DNA or RNA) .
C) A single-stranded segment of amino acids encoded by a target sequence (either DNA or RNA) .
D) All of the above.