Step 1: Understanding the Concept:
This question requires factual knowledge about the Konkan Railway project, a significant piece of infrastructure in India.
Step 2: Detailed Explanation:
Let's evaluate each statement:
(A) It was constructed in 1998. This statement refers to the completion and inauguration of the full line. The project was completed and opened to full traffic on January 26, 1998. So, this statement is considered correct.
(B) It connects Roha in Maharashtra to Mangalore in Karnataka. This is correct. The railway line runs along the Konkan coast, starting from Roha, south of Mumbai, and ending at Thokur, just north of Mangalore.
(C) It is considered an engineering marvel. This is correct. The construction of the railway through the rugged terrain of the Western Ghats involved building over 2,000 bridges and 91 tunnels, making it one of the most challenging engineering projects in the country's history.
(D) The states of Maharshtra, Tamil Nadu and Karnataka are partners in it. This is incorrect. The Konkan Railway Corporation Ltd. is a joint venture between the Ministry of Railways and the states of Maharashtra, Goa, and Karnataka. Tamil Nadu is not geographically on the Konkan coast and is not a partner in this project.
Thus, statements (A), (B), and (C) are correct.
Step 3: Final Answer:
The correct option is the one that includes only statements (A), (B), and (C).