The defining characteristic of the intertidal zone is that it is submerged with water during high tide and exposed to the air during low tide. The zone can take many forms, from sandy beaches to rocky cliffs. It is common for the intertidal zone to change frequently, since it is constantly battered by crashing waves.
Hope this helped.
I thought it was (d) but I might be wrong
The mutated proteins are random changes in the sequence while the normal sequence was meant to be how it is
Hasan most likely has rickets
Rickets is a disease of children which is caused by vitamin D deficiency. Rickets softens and weakens bones in affected children. Symptoms of rickets include bowed legs, pain in the bones, stunted growth, trouble sleeping and muscle weakness. Rickets can lead to other health problems such as intellectual disability and muscle spasms.
Elevation because it means the level of a point surface height above the sea level