From left to right, which is the sequence of the
complementary strand of DNA in this molecule?

Answer: Option A) A-C-T-T-G
Explanation:
The base sequence on a strand of DNA is usually paired to specific complimentary bases. These specific pairings are as follows:
Adenine (A) pairs with Thymine (T)
Guanine (G) pairs with Cytosine (C). So when you find A replace with T, so also replace C with G and vice versa.
Thus, the complimentary sequence of the T-G-A-A-C DNA strand is A-C-T-T-G