Final answer:
Monica requests Rhoda's assistance to carry cupcakes that were left upstairs by Miss Fern, who is referred to as 'the old scatterbrain'.
Step-by-step explanation:
From the dialogue given, Monica asks Rhoda to help her carry the cupcakes down. She refers to Miss Fern as 'the old scatterbrain' and indicates that the cupcakes were left upstairs. By asking Rhoda for help, Monica is delegating the task of transporting the cupcakes to a different location. Therefore, the correct answer to what Monica is asking Rhoda to do is a) Help carry cupcakes.