Ooh Chemistry sucks. Try looking up parts of the question.
The answer would be A) Physical Change. When the silver tarnishes it is still remnants of silver. If it were B, the silver would change into a different substance.
If mirrors did not reflect light, then we would be able to see through it.
Similars are they both contain all 4 biomolcules, have ribsomes, can be uniceullar, have cell membranes and cell wall, have DNA, and similar metabolism