A material is said to be perfectly elastic if A. It regains its original shape on removal of the load B. It regains its original shape partially on removal of the load C. It does not regain its original shape at all D. None of these

The correct answer is A. A material is said to be perfectly elastic if it regains its original shape on removal of the load.

Option B is incorrect because a material that regains its original shape partially on removal of the load is said to be partially elastic.

Option C is incorrect because a material that does not regain its original shape at all is said to be plastic.

Option D is incorrect because it is not one of the possible answers.