The impact of the assembly line was most greatly felt by which group

Car manufacturers.

Explanation:

Car production is a demanding process. The production revolution was presented by Henry Ford, who involved conveyor belts in the process. It happened in early 1913, and the process changed the way it was produced globally. The introduction of this production method led to more productive work, and there was much less waste. Replacement parts are a truly revolutionary moment in car production. This production way brought huge benefits to workers in Ford, less working hours and higher salaries.

b, public works good luck