The root word mit means "send." what prefix can you add to create a word meaning "to send across"? inter over semi trans

The correct answer is trans.
The root word is the most basic part of the word you would use to add prefixes and suffixes to in order to create a new word. In the case of transmit, the root word mit means to send, whereas the prefix trans means across, so those two parts combined create a verb which means to send across.