Moving Average Explanation and Calculation

I am trying to understand the following question:

If the overall trend of the dependent variable is decreasing, will a k-period
moving average be greater than a moving average obtained with k minus 1 periods?

If so, why?

I cannot seem to grasp this concept and I am looking for some clarification.

nvestopedia explains Moving Average – MA…
Moving averages are used to emphasize the direction of a trend and to smooth out price and volume fluctuations, or “noise”, that can confuse interpretation. Typically, upward momentum is …

This solution explains the concept of moving average.