Question

If the nucleotide sequence of a strand of DNA is CTAA, what is the nucleotide sequence on its complementary strand? A. CTAA

Answer 1

The complementary strand will contain the corresponding 'pair partners'. Thus, if your sequence is CTAA, the complementart strand will be G..T (you fill in the gap...?)!

Answer 2

(Hint: The complementary strand will read '.AT.' (...you fill in the ends...?))! ;)

Answer 3

Indeed...! - Calliope has indicated the hydrogen bonds between the nucleotide 'pair partners'. By combining the hints above you probably obtained the following result:
C - T - A - A
||| || || ||
G - A - T - T - where this line to the left is your complementary strand: GATT !