Given
The coordinates of the triangle ABC are:

The coordinates of the triangle DEF are:

The sequence of transformation that maps triangle ABC onto triangle DEF is
1. Reflection over the x-axis
The rule for the reflection over the x-axis:

Applying this rule to the triangle ABC gives:

2. Reflection over the y-axis:
The rule for the reflection over the y-axis:

Applying this gives :

Hence, the correct option is option A