The correct answer is: b) Building roads and bridges in rural areas.
The Sikkim Rural Roads Project is a government initiative to improve the infrastructure in rural areas of Sikkim. The project focuses on building roads and bridges, as well as improving access to water and sanitation. The project is expected to benefit over 1 million people in Sikkim.
Option a) is incorrect because the project does not focus on upgrading highways connecting major cities.
Option c) is incorrect because the project does not focus on developing scenic tourist routes.
Option d) is incorrect because the project does not focus on promoting electric vehicles.