Explanation:

- Nitin Gadkari was the Union Minister of Road Transport and Highways as of July 2020. He played a key role in infrastructure development and policy reforms in the transport sector.

- Kiren Rijiju has held several portfolios, such as Minister of Youth Affairs and Sports and Minister of State for Home Affairs, but was not the Minister of Road Transport and Highways during this period.

- Thawar Chand Gehlot served as the Minister of Social Justice and Empowerment, focusing on policies for marginalized communities.

- Piyush Goyal had various responsibilities including Minister of Railways and Commerce and Industry, but not Road Transport and Highways.