Which one of the following is the correct statement for respiration in humans?

Cigarette smoking may lead to inflammation of bronchi.

Neural signals from pneumotoxic centre in pons region of brain can increase the duration of inspiration.

Workers in grinding and stone-breaking industries may suffer from lung fibrosis.

About \( 90 \% \) of carbon dioxide \( \left(\mathrm{CO}_{2}\right) \) is carried by haemoglobin as carbamino-haemoglobin.