That is the problem.
Read the entire question again:
The beneficiary is in the United States and will apply for adjustment of status to that of a lawful permanent resident at the U.S. Citizenship and Immigration Services (USCIS) office in:
61.a. City or Town
61.b. State
When you put in an answer for 61a and 61b, you were saying the beneficiary was in the U.S. and will adjust status in the U.S.
For your mother, the ISO reading the petition saw that you meant to answer:
The beneficiary will not apply for adjustment of status in the United States, but he or she will apply for an immigrant visa abroad at the U.S. Embassy or U.S. Consulate in:
62.a. City or Town
62.b. Province
62.c. Country
For your father, the ISO did not give you that concession. That ISO held you to your error.
Hire an immigration attorney to handle these cases moving forward.