Answer:
Option-B
Explanation:
The brain is an organ composed of neurons which controls all the voluntary and involuntary of animals. In humans, the brain is located in the skull where the brain is suspended in a fluid called cerebrospinal fluid.
As humans ages and becomes old aged, the neurons in the brain losing their ability to perform their function, if they are lost they cannot be regenerated.
The lesions appear on the white matter of the brain and the brain shrink. Due to these known and other unknown features, the process controlled by these neurons become inadequate and shows slower brain processing and weak memory.
Thus, Option-B is the correct answer.
Scientists believe that at first these bears scavenged seal carcasses that had washed ashore, and gradually began to hunt the seals by waiting at the water's edge as the seals surfaced to breathe. This is believed to be an important step in the evolution of a new bear species, the polar bear
Over time the new polar bears were used to the cold climate and learnt how to fish, they then separated from the grizzly bears, they developed new creatures which would help them survive in one of the most dangerous climate.
