Read the text below completing its sense with the alternatives presented in questions 36 to 39.

Bilingualism good for the brain, researchers say

Neuroscience researchers are increasingly coming to a consensus that bilingualism has many positive consequences for the brain. Several such researchers traveled to this month's annual meeting of the American Assn. for the Advancement of Science in Washington, D.C., to present their findings. Among them:

• Bilingual children are more effective [1] ____________.

• Adults who speak more than one language do a better job prioritizing information in potentially confusing situations.

•Being bilingual helps ward off early symptoms of Alzheimer's disease in the elderly.

These benefits come from having a brain that's constantly [2]_________ two — or even more — languages, said Ellen Bialystok, a psychology professor at York University in Toronto. For instance, a person who speaks both Hindi and Tamil can't turn Tamil off even if he's speaking to only Hindi users, because the brain is constantly deciding which language is most appropriate for a given situation. This constant back-and-forth between two linguistic systems means frequent exercise for the brain's so-called executive control functions, located mainly in the prefrontal cortex. This is the part of the brain tasked with focusing one's attention, ignoring distractions, holding multiple pieces of information in mind when trying to solve a problem, and then flipping back and forth between them.

To test one's ability to identify pertinent nuggets while being bombarded with extraneous information, scientists use something called the Stroop test. Subjects are presented with a word for a particular color and asked to identify the color of ink it's printed in. So if the word is "blue" and it's printed in blue, no problem. If, on the other hand, the word "blue" is printed in red, they have to sort out which piece of information — the color of the ink or the color being spelled out— is the one they need.

"This is extremely hard to do, because it's terribly difficult to [3] _________ the information from the word," Bialystok said. He theorizes that bilingual people do better in this test because they are used to prioritizing information in potentially confusing situations all day.

Bilingual speakers rarely use the wrong language with a monolingual speaker. But if the listener also knows both languages, they can choose [4] ________ between them to most accurately express their thoughts.

By Amina Khan, Los Angeles Times

Choose the only alternative that fully completes the text (grammatically and logically) in each question from 36 to 39.