What is the best way to change the sentence below from active voice to passive voice?

expert campers advise others to bring extra batteries for the flashlight when camping.

a. you might advise someone to bring extra batteries for the flashlight when camping.
b. when camping, extra batteries should be brought for the flashlight.
c. when camping, a person might advise another person to bring extra batteries for the flashlight.
d. some people would advise you to bring extra batteries for the flashlight when camping.

Pls, i really need on this question?

How does this excerpt develop the central idea that espionage during the civil war was often carried out by untrained citizens? it enhances the reader’s understanding by explaining why training was unnecessary. it changes the reader’s perception of what information a spy was able to obtain. it explains an ordinary person’s motivation for conducting espionage against the enemy. it adds moral complexity to espionage, due to the use of secret and dangerous methods.

If music be the food of love, play on; give me excess of it, that, surfeiting, the appetite may sicken, and so die. that strain again! it had a dying fall: o, it came o'er my ear like the sweet sound, that breathes upon a bank of violets, stealing and giving odour! now read the excerpt from "the love song of j. alfred prufrock." for i have known them all already, known them all: have known the evenings, mornings, afternoons, i have measured out my life with coffee spoons; i know the voices dying with a dying fall beneath the music from a farther room. what does the phrase "dying fall" most likely mean in both excerpts