In the scenario of Sterling Equity$$s leveraged buyout of AutoTech Inc., a manufacturer of automotive components, a detailed analysis of the first year$$s financial outcomes post$-$acquisition reveals significant changes. Prior to the acquisition, AutoTech Inc. was facing production bottlenecks due to inefficient manufacturing processes and overstocked inventory. Post$-$acquisition, the company$$s revenue increased from $$50$ million to $$60$ million, operating margins improved from $10\%$ to $12\%,$ and the inventory turnover ratio rose from $5$ to $6$ times a year. Given this context, which of Sterling Equity$$s strategies is most likely to have driven these positive financial results?

A$)$Introduction of advanced automation technologies in manufacturing.

B$)$Expansion into new automotive markets, including electric vehicles.

C$)$Streamlining of supplier contracts and renegotiation for better terms.

D$)$Implementation of lean manufacturing principles and just$-$in$-$time inventory.