To have a career in transportation or manufacturing, the most relevant degree among the options you provided would be:
Bachelor’s degree in logistics and transportation.
This degree directly relates to the planning, execution, and management of the flow of goods and services, which is essential in both transportation and manufacturing sectors.
While an associate's degree in welding and fabrication could also offer job opportunities in manufacturing, the bachelor's degree in logistics and transportation is specifically tailored for careers focused on transportation systems and supply chain management.
The doctorate in research and development may be relevant for advanced roles, but it is typically geared more towards academic or high-level research positions rather than general careers in transportation or manufacturing. A master’s degree in political science is not directly applicable to these fields either.