Answer:
C
Step-by-step explanation:
Attached is the structure of a hydronium ion.
A is not the answer since evaporation is a phase change, not a structural change. We are looking for a structural change since we are trying to form a hydronium ion.
B is not the answer since two water molecules bonded together would not produce the attached structure. It would produce a structure with two oxygens and four hydrogens.
C is the answer since water bonding to another hydrogen produces a hydronium ion.
D is not the answer since this combination would produce water.
E is not that answer since splitting a water molecule in half would take from the structure when you are actually supposed to add to it.