The Border Trade Center, a key facility for cross-border commerce, is located in:

Champhai
Lunglei
Zokhawthar
Lawngtlai

The correct answer is: c) Zokhawthar.

Zokhawthar is a town in the Indian state of Mizoram. It is located on the border with Myanmar and is the site of the Zokhawthar Border Trade Centre, a key facility for cross-border commerce. The centre was established in 1995 and is the only official border trade point between India and Myanmar. It is a major trading hub for goods such as rice, vegetables, fruits, and timber.

The other options are incorrect. Champhai is a town in the Indian state of Mizoram. It is located about 100 km from Zokhawthar. Lunglei is a town in the Indian state of Mizoram. It is located about 150 km from Zokhawthar. Lawngtlai is a town in the Indian state of Mizoram. It is located about 200 km from Zokhawthar.