Teacher asks, class if you could only bring one item to a island?

So a schoolteacher asks the class, if you were going to a deserted island and you could bring only one item what item would each of you bring?

Robert answers first saying, "I would bring a toothbrush to keep my teeth clean"

Cynthia is next and says "I would bring a picture of my family so I could think about them"

Dave is next and says "I would bring a long book so I could have something to do"

Albert is next and says "I would bring matches to start a fire"

Christine is next and says "I would bring a tent so I have something to sleep in"

Julia is next and says "I would bring a satellite phone, you all can hang out on that island I am going to call for a ride home"