Q. Ultrasounds are used extensively in industries and for medical purposes. Which among the following is / are applications of Ultrasound? 1. Detect cracks and flaws in metal blocks 2. Echocardiography 3. Treatment of Kidney stones 4. Cleaning of odd shaped objects Select the correct option from the codes given below:

• A. Only 1 & 2
• B. Only 1, 2 & 3
• C. Only 1, 3 & 4
• D. 1, 2, 3 & 4

Correct Answer: D