Nucleotide position of Codons

Which is true about the nucleotide position of codons?
a.a nucleotide at the third position of a codon pairs with a nucleotide in the third position of the anticodon and can sometimes results in nonstandard pairings.
b.a nucleotide at the third position of a codon pairs with a nucleotide in the third position of the anticodon and can sometimes results in nonstandard pairings
c.Because many synonymous codons differ only in the third nucleotide position,when a nonstandard pairing occurs at the third nucleotide position, the correct amino acid is not likely to be insertedm leading to an error in peptide sequence.
d, because many synonymous codons differ in only in the third nucleotide position, even if a nonstandard pairing occurs at the third nucleotide position, the correct amino acid will likely still be inserted.