By the french language.
After the Norman invasion and conquest of Britain, they were subject to change the official language to french and english was no longer allowed nor spoken on court. This is also the reason for some french words in the english language nowadays.
The correct answer is:
On the other hand.
"He looked forward to visiting with old friends. Greta, on the other hand, dreaded seeing her old boyfriend."
This phrase is showing Greta and Fred are having different feelings in that moment, creating a contrast between both of them.
