What was my mother’s reaction when I forgot to do the washing up?

Choosing "She lost her temper" accurately captures a likely emotional response when someone forgets to do a household chore like washing up. This reaction suggests a strong emotional response, indicating that the mother was frustrated or angry about the oversight.

The other options convey different levels of emotional engagement. Ignoring someone may imply a lack of care or concern, which doesn't fit the context of forgetting tasks in a household scenario. Being indifferent suggests a level of emotional neutrality that seems too mild for a scenario where someone might feel let down. Feeling disappointed, while understandable, might not convey the immediacy or intensity of a temper loss and does not encompass the full range of possible reactions, which can include raised voices or a demand for accountability.

Thus, "She lost her temper" best illustrates a reaction involving an escalation of emotions directly related to the frustration and potential disappointment felt in such a situation.