Click on the box next to each meaning for the prefix un-. beginning
out of
opposite of
full of
near
not

the prefix un means not. it also means to be the opposite of.

a. "to practice" is the best phrase to complete the sentence.

explanation:

during the summer, she likes to practice her soccer skills so that she is ready to play in the fall.

(note that : all the other options "the practicing of", "practice for" and "to do a practice on" are inappropriate as they make the sentence grammatically incorrect.)