Which one of the following is the correct statement for respiration in humans ?
A. cigarette smoking may lead to inflammation of bronchi
B. Neural signals from pneumotaxic centre in pons region of brain can increase the duration of inspiration
C. workers in grinding and stone-breaking industries may after from lung fibrosis
D. About 90% of carbon dioxide `(CO_(2))` is carried by haemoglobin as carbamino haemoglobin
