One end of a light spring of spring constant k is fixed to a wall and the other end is tied to a block placed on a smooth horizontal surface. In a displacement, the work by the spring is `1/2kx^2`. The possible cases are
A. the spring was initially compresed bya distance x and was finaly in its natural length
B. it was initially in its natural distance x and finally was in its natural length
C. it was initially in its natural lenth and finaly in a compressed position.
D. it was initially in its natural length and finally in a stretched positon.