Consider the following four statements (a-d) and select the option which includes all the correct ones only `:-`
(a) All the time of inspiration , contraction in diaphragm and external intercostal muscles take place.
(b) Normal breathing is also called as abdominal breathing.
(c ) Expiration during sneezing, coughing, yoga is normal expiratio during which IICM and abdominal muscles relax.
(d) Inspiration can occur if the pressure within lungs (intra pulmonary pressure) is more than the atmospheric pressure.

Options

A. Statement `(a), (b), (c ) ,(d)`
B. Statements `(a)` only
C. Statement`(a), (b) ,(c )`
D. Statement `(a)` and `(b)`

Answer

To solve the question, we need to evaluate each of the four statements (a-d) regarding human physiology, particularly focusing on respiration. Let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Statement (a):** "All the time of inspiration, contraction in diaphragm and external intercostal muscles take place."
- **Analysis:** This statement is true. During inspiration, the diaphragm contracts and moves downward, and the external intercostal muscles contract to expand the thoracic cavity, which decreases the pressure in the lungs and allows air to flow in.

2. **Statement (b):** "Normal breathing is also called as abdominal breathing."
- **Analysis:** This statement is false. Normal breathing is referred to as "thoracic breathing" or "pulmonary breathing," where primarily the diaphragm and intercostal muscles are involved. Abdominal breathing is more pronounced during forced breathing or deep breathing.

3. **Statement (c):** "Expiration during sneezing, coughing, yoga is normal expiration during which IICM and abdominal muscles relax."
- **Analysis:** This statement is false. During expiration, especially in forced expiration (like sneezing or coughing), the internal intercostal muscles (IICM) contract to help push air out of the lungs. The abdominal muscles may also contract to assist in this process.

4. **Statement (d):** "Inspiration can occur if the pressure within lungs (intrapulmonary pressure) is more than the atmospheric pressure."
- **Analysis:** This statement is false. Inspiration occurs when the intrapulmonary pressure is less than atmospheric pressure, allowing air to flow into the lungs. If the pressure in the lungs is greater than atmospheric pressure, expiration occurs instead.

### Conclusion:
After analyzing all four statements, we find that:
- **Correct Statement:** (a)
- **Incorrect Statements:** (b), (c), (d)

Thus, the option that includes all the correct statements only is **option 2**, which indicates that only statement (a) is correct.