Answer:
A. AGAT
Explanation:
Remember these are the nitrogenous base pairs:
Adenine (A) and Thymine (T)
Cytosine (C) and Guanine (G)
So in TCTA
The T would change to A
The C would change to G
The T would change to A
The A would change to T
And we would get AGAT
Therefore the answer is A
