I assume "An" is a name where you are. Note that the word you need is "protect".
c) and d) are both grammatical and possible.
b) is not grammatical. We don't say "Xxx suggested me verb_+ing". We say "XXX suggested to me that I verb ..."
a) is incorrect on two counts. 1 - the word "use" appears twice. 2 - saying "your files" at the end doesn't make sense.
Student or Learner