Answer:
Kenji's alfalfa opportunity cost:
each bushel of Alfalfa cost 4 bushel of barley.
Lucia's alfalfa opportunity cost:
each bushel of Alfalfa cost 5 bushel of barley.
Step-by-step explanation:
the opportunity cost is based on the output resinged when chosing a particular good.
In this case, the opportunity cost of barley is the Alfalfa and, for th Alfalfa the Barley that the farmer could have made.
Kenji's:
20 Barley / 7 alfalfa = 4 barley
each bushel of Alfalfa cost 4 bushel of barley.
Lucia's:
40 barley / 8 alfalta = 5 barly
each bushel of Alfalfa cost 5 bushel of barley.
DISCLAMER:
The table suggest two different names
I will assume the top value are from Lucia as those gives the absolute advantage stated in the question.
"Lucia has an absolute advantage in the production of barley, and Lucia has an absolute advantage in the production of alfalfa"
and the bottom from Kenji.