The given sentence is: "Since I was planning on a Euro tour, I decided to _____________ my French."
The context of the sentence suggests that the speaker intends to improve or refresh their knowledge of the French language before undergoing the planned travel. Among the provided options, the most suitable choice is "brush up on," which means to improve one's existing skills or knowledge in a particular area, thus filling in the blank as: "Since I was planning on a Euro tour, I decided to brush up on my French."
Option
Meaning
try my hand at
Attempt doing something for the first time
make up for
Compensate for something
brush up on
Revise or improve skills or knowledge
master the art of
Become highly skilled at something
Among these meanings, "brush up on" is the action associated with refreshing one's knowledge or skills, making it the most appropriate option in this context.