Why, in$$ practice, is it difficult for the average investor to make a profit from an interest carry$$ trade?

Part $4$

A$.$

Borrowing rates for the average investor are much higher than$$ short$-$term Treasury rates.

B$.$

The average investor often overestimates inflation rates resulting in negative real returns on$$ long$-$term investments.

C$.$

It is very difficult for the average investor to determine$$ short$-$term and$$ long$-$term interest rates.

D$.$

The average investor does not have access to$$ long$-$term investments, and can only access them through expensive brokerage arrangements.