Explanation:

Premises:
- Whenever my mother scolds me, I either hide behind my father or complain to my grandma.

Conclusion:
- If I did not complain to my grandma and I did not hide behind my father, then my mother must not have scolded me.

Analysis:
Let's break down the options and analyze them one by one:

Option A:
- If I did not complain to my grandma and I did not hide behind my father, then my mother must not have scolded me.
- This statement aligns with the premise that whenever my mother scolds me, I either hide behind my father or complain to my grandma.
- If I didn't do either of those actions, it implies that my mother did not scold me.
- Therefore, option A is correct.

Option B:
- If I complain to my grandma or I hide behind my father, then my mother must have scolded me.
- This statement contradicts the premise that whenever my mother scolds me, I either hide behind my father or complain to my grandma.
- The option states that if I perform either of those actions, it implies that my mother scolded me.
- However, there could be other reasons for me to complain to my grandma or hide behind my father, not necessarily related to my mother scolding me.
- Therefore, option B is not necessarily true.

Option C:
- If my mother does not scold me, I will neither hide behind my father nor complain to my grandma.
- This statement also contradicts the premise that whenever my mother scolds me, I either hide behind my father or complain to my grandma.
- The option implies that if my mother does not scold me, I will not perform either of those actions.
- However, there could be other reasons for me to hide behind my father or complain to my grandma, even if my mother did not scold me.
- Therefore, option C is not necessarily true.

Conclusion:
Considering the analysis above, option A is the correct answer. It aligns with the given premise and logically follows from it.