Answer:
d) Both a and b are correct
Explanation:
Displacement: It is defined as the distance between initial and final position during motion.
Distance: It is defined as the total path length traveled by object
Or
It is the distance of one place from other place.
Student said that the displacement between my dorm and the lecture hall is 1km.
It is not displacement .It is distance or we say path length.
Therefore, he is using incorrect physical quantity for the information provided.
He should have called distance 1 km or path length 1 km.
Option d is true.