b.546 4619689, 475186, 12345
c. 123456, 753824659, 34964
d. 1234561, 78478, 9312864
e. 67898, 12324, 98678
f. 7532, 356181, 419 65019
Each of the above triplets, encrypted by a distinct substitution code, depicts two cities (townships) and a corresponding country (or state).
Up to you to decode.