Answer:
A. oil, B. electricity.
Step-by-step explanation:
The oil began to be used in the rising automobile industry in the 1900s, due to the development and application of internal combustion engines, which were developed by Diessel and Otto in the 1870s and 1880s.
Electricity began to be used in urban lightning in the 1890s, thanks to development of Direct and Alternative Current Engines by Edison and Tesla.
Water power began to be used for electricity generation from 1930s and atomic power from the 1950s.