"With the right motivation, anyone can achieve excellence in any field of endeavor." --unknown source
How rational is it?It is based on solid evidence?Have all sides of the issue been considered?Would most reasonable people make the same conclusion based on this evidence?

no

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.)

c. should have been

hope this

a test i would say we need more information : (