Correct option is A
Explanation-
Statement analysis-
Statement A: At the end of quiet expiration the tendency of the lung to recoil from chest wall is balanced by the recoil of chest wall in opposite direction, and intrapleural pressure is subatmospheric.
At the end of quiet expiration (resting state), the lung recoils inward and the chest wall outward, creating a negative (subatmospheric) pressure in the intrapleural space. So, this statement is correct.
Statement B: At the start of inspiration the intrapleural pressure is subatmospheric.
Intrapleural pressure is already subatmospheric before inspiration begins, and becomes even more negative during inspiration. So, this statement is correct.
Statement C: The intrapleural pressure becomes more negative during inspiration.
As the thoracic cavity expands, the intrapleural pressure decreases further, becoming more negative to help lung expansion. So, this statement is correct.
Statement D: The intrapleural pressure attains value above atmospheric pressure during expiration.
Intrapleural pressure remains negative even during expiration (though it becomes less negative). It rarely becomes positive, except in forceful expiration or conditions like pneumothorax. So, this statement is incorrect.
Statement E: The intrapleural pressure becomes positive (relative to atmospheric pressure) during strong inspiratory efforts.
During strong inspiratory efforts, the intrapleural pressure becomes even more negative, not positive. So, this statement is incorrect.
Correct combination: A, B, and C
Final Answer: Option a
