I am pretty sure it is B. diaphragm hope it help
It is probably the l<span>amellae.
The lamellae are sheets of bony matrix. This bony matrix is produced by o</span>steoblasts, which are cells that synthesise collagen<span> and specialised proteins like </span>osteocalcin<span> and </span>osteopontin. These are then the most important constituents of the bony matrix.
Answer:
pollution doesn't nessairly stay in the atmosphere, it is moved throughout the atmosphere and can be removed by a natural process.