Which english engineer invented a special furnace that could cheaply turn iron into steel paving the way for a mass production

Sir Henry Bessemer was the English engineer who invented a special furnace that could cheaply turn iron into steel paving the way for a mass production.

He was an inventor and engineer who created the first process for manufacturing steel inexpensively (1856), giving way to the development of the Bessemer converter. He was knighted in 1879. He was soon devoted to metallurgy. His father was an engineer and typefounder.

it was the first amendment

i don't think it's c or d. i think it's either a or b.

hope this .