4. (3 points) Answer True or False (a) Mapping reduction is a transitive relation. In other words, for all languages A B C over , (b) Mapping reduction is a symmetric relation. In other words, for all languages A and B over (c) Mapping reduction is a reflexive relation. In other words, for every language A over if A Em B and BEm C then A Em C , if A m B then BSnA. A Sm A