Correct Answer: Both assertion and reason are true, and the reason is the correct explanation of the assertion.

Solution : The correct answer is (a) Both assertion and reason are true, and the reason is the correct explanation of the assertion.

The assertion that the National Career Service (NCS) portal serves as a single-window platform for job seekers and employers is true. The NCS portal, established by the Government of India, is designed to connect job seekers with employers by providing a centralized platform for various employment-related services. It acts as a single-window platform where both job seekers and employers can access multiple services and resources related to employment.

The reason provided is also true. The NCS portal facilitates job matching, career counseling, and skill assessments for individuals. It offers a range of services, including job search, resume creation, skill development courses, career guidance, and access to employment opportunities. By providing these services, the NCS portal aims to assist individuals in finding suitable employment and help employers in finding qualified candidates.

Therefore, both the assertion and the reason are true, and the reason correctly explains why the NCS portal serves as a single-window platform for job seekers and employers, making option a the correct choice.