A passage is given below with five blanks labelled (A)-(E). Below the passage, five options are given for each blank. Choose the word that fits each blank most appropriately in the context of the passage, and mark the corresponding answer.
The first of our three brains to evolve is what scientists call the reptilian cortex. This brain sustains the ____(A)____ activities of animal survival such as respiration, adequate rest and a beating heart. We are not required to consciously 'think' about these activities. The reptilian cortex also houses the 'startle centre', a mechanism that ___(B)___ swift reactions to unexpected occurrences in our surroundings. That panicked lurch you experience when a door slams shut somewhere in the house or the heightened awareness you feel when a twig cracks in a nearby bush while out on an evening stroll are both examples of the reptilian cortex at work.
Although the lizard may stake a claim to its habitat, it exerts total indifference toward the well-being of its young. Listen to the ____(C)____ squeal of a dolphin separated from its pod or witness the sight of elephants mourning their dead, however, and it is clear that a new development is at play. Scientists have identified this as the limbic cortex. Unique to mammals, the limbic cortex impels creatures to nurture their offspring by delivering feelings of tenderness and warmth to the parent when children are nearby. These same sensations also cause mammals to develop various types of social relations and kinship networks.
Only human capabilities extend far beyond the scope of these two cortexes. Humans eat, sleep and play, but we also speak, plot, rationalise and debate finer points of morality. Our unique abilities are the result of an expansive third brain – the neocortex – which engages with logic, reason and ideas. The power of the neocortex comes from its ability to think beyond the present, concrete moment. While other mammals are mainly restricted to ___(D)___ actions (although some, such as apes, can learn and remember simple lessons), humans can think about the 'big picture'.
The neocortex is also responsible for the process by which we decide on and commit to particular courses of action. Strung together over time, these choices can accumulate into feats of progress unknown to other animals. ____(E)____ a better grade on the following morning’s exam, a student can ignore the limbic urge to socialise and go to sleep early instead. Over three years, this ongoing sacrifice translates into a first-class degree and a scholarship to graduate school; over a lifetime, it can mean ground-breaking contributions to human knowledge and development. The ability to sacrifice our drive for immediate satisfaction in order to benefit later is a product of the neocortex.