Inside pressure in a hollow soap bubble in the air is : (where d is the diameter of the bubble)

• A. <img src="/_files/images/civil-engineering/hydraulics/159-7.233-1.png">
• B. <img src="/_files/images/civil-engineering/hydraulics/159-7.233-2.png">
• C. <img src="/_files/images/civil-engineering/hydraulics/159-7.233-3.png">
• D. <img src="/_files/images/civil-engineering/hydraulics/159-7.233-4.png">