Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Interest rates increasebecause of a higher price level, lead to lower levels of consumption and investment. What’s the description talk about and it can be used to explain：
Option A:interest rate effect, the downward slope of the aggregate demand curve.
Option B:real exchange rate effect, the downward slope of the aggregate demand curve.
Option C:interest rate effect, the upward slope of the aggregate supply curve.

Answer: A