Which of the following functions from `AtoB` are one-one and onto? `f_1={(1,3),(2,5),(3,7)};A={1,2,3},B={3,5,7}` `f_2={(2, a),(3, b),(4, c)};A={2,3,4},B={a , b , c}` `f_3={(a , x),(b , x),(c , z),(d , z)}; A={a , b , c , d},B={x , y , z}`