Water at 50 degrees C can be obtained by mixing together which one or more of the following combinations?

Water at 50 degrees C can be obtained by mixing together which one or more of the following combinations? Which of the others would have final tempertures higher than 50 degrees C  and which lower than 50 degrees C?  What will be the final tempertures for these combinations?

a.  1 kilogram of ice at 0 degrees C and 1 kilogram of steam at 100
      degrees C.
b.  1 kilogram of ice at 0 degrees C and 1 kilogram of water at 100
      degrees C.
c.  1 kilogram of water at 0 degrees C and 1 kilogram of steam at 100
      degrees C.
d.  1 kilogram of water at 0 degrees C and 1 kilogram of water at 100
      degrees C.