Answer: nucleotide A will bind to nucleotide T during DNA replication.
Explanation:
In DNA replication, Adenine(A) pairs up with its complementary base Thymine(T). The DNA polymerase which is an enzyme ensures that the nucleotide with base T binds to the base A of parental nucleotide.
The correct answer is D. Bird flu.
Polio and smallpox are very rare today as they were eradicated hundreds of years ago and TB has been around for maybe thousands of years. Bird f!u was discovered in 1957.