The world`s highest rail bridge is being constructed in the State of J & K. The bridge will be built on the Chenab River.
Option 1: Jhelum River - This is not the correct answer. The highest rail bridge is not being constructed on the Jhelum River.
Option 2: Chenab River - This is the correct answer. The world`s highest rail bridge is being constructed on the Chenab River in the State of J & K.
Option 3: Indus River - This is not the correct answer. The highest rail bridge is not being constructed on the Indus River.
Option 4: Ravi River - This is not the correct answer. The highest rail bridge is not being constructed on the Ravi River.
Therefore, the correct answer is option 2, Chenab River.