What significant invention made both bicycle and automobile transportation possible?
a.
combustion engine
c.
dunlop tires
b.
ford's model-t
d.
steam engine

The correct answer is C) Dunlop Tires.

Dunlop Tires made both bicycle and automobile transportation possible.

Pneumatic tires were invented in Scotia in 1839. They were invented by Robert Thomson. He created a process called vulcanization, adding sulfur to rubber and used for horse-drawn carriages. John Boyd Dunlop applied the same principle but to bicycles and later did the same with tires for cars.

c

Explanation:

i think it was   tsar alexander ii

all of the