Which of the following best defines the word locomotive?
a.
a self-propelled engine, powered by steam, diesel, or electricity, for pulling or, sometimes, pushing
b.
a series or row of objects or parts
c.
passing or extending across a continent
d.
a horse-drawn coach that traveled over a fixed route with passengers, parcels, etc.

Please select the best answer from the choices provided

A
B
C
D