After experiencing prolonged and seemingly inescapable physical abuse from her husband, kayla became increasingly depressed and hopelessly resigned to her situation. her reaction best illustrates:

This is an example of learned helplessness. Because the situation was unchangeable in the past, Kayla learned that there was nothing that she could do, and was dissuaded from taking action. This state of helplessness will persist even after Kayla is removed from the abusive relationship, and takes intense therapy to correct.

Complementary goods. they go together, thats why one price increase and the others demand increases