Answer:
Option A (k < -1).
Explanation:
Enlargement is one of the linear transformations which changes the size of the shape formed by a combination of some points in the exact proportion. For enlargement (also called dilation), there are two parameters required: the center of enlargement, according to which the transformation occurs, and the scale factor, the size by which the transformation is done. The scale factor can be of any number k. If k is larger than 1 or -1, then it will cause enlargement. If k is between -1 and 1, it will cause anti-enlargement. The magnitude of k determines the size and the sign of k determines the direction. So in this case, k < -1 will cause the enlargement: even though the scale factor is less than -1, but it will enlarge the shape on the opposite direction. Option B and Option C cause anti-enlargement and Option D cause no enlargement or anti-enlargement. So Option A is the correct answer!!!