The word concerted in paragraph 2 mostly means _______.

Câu hỏi: Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 44 to 50.
Are you addicted to technology? You probably think you aren't, but just take a minute to look more closely at your daily life. Your mobile phone alarm wakes you up, and the first thing you do is check if you have any new email messages, maybe even check the weather forecast so you can decide what to put on. On the way to college, you pop in your MP3 player earbuds and listen to some music you downloaded the previous night. Once at college, your teacher is using an interactive whiteboard. Some students are using tablets to take notes. When the class has finished, you look at your mobile to see that your friend Lucy has texted to tell you where everyone's meeting for lunch. Are you still so sure you could relinquish technology?
Increasing numbers of people, however, are taking the decision to go technology free. This involves making a concerted effort to remove all technological devices from their lives. Take Laura Jo Wegman and Donovan Corliss. Not only have they got rid of the obvious technology, such as computers and TVs, they have also modified their cooker to remove the LED display and have a rotary dial telephone. ‘I think TV and internet and phones become such a time suck that people feel they don't have time for anything else,’ explains Corliss. He goes on to explain how much more time they have now. The family now play musical instruments, make bread and even talk to each other! They say it's revolutionized their lives.
And this family isn't alone. The 'unplugging' movement is growing fast. Not everyone takes it as seriously as Wegman and Corliss, but more and more people are adopting new approaches to technology. For example, Tiffany Shlain pioneered the idea of having a technology-free day once a week, usually on a Saturday. Shlain says that ‘It's definitely harder to make plans,’ as, instead of sending lots of texts, she needs to make an arrangement and stick to it. And as Shlain points out, the quality of interaction with people who aren't constantly checking their mobiles is much better.
Another popular activity is to take a digital detox retreat, a long weekend hiking out in the countryside with no gadgets. It allows you to develop the skill of finding your way without Google Maps, and seeing the beauty of nature without having to take a digital photograph of it. So why not try reverting back to a tech-free world, even if just for a while? And, if you can't even imagine kicking the habit, ask yourself if you really aren't addicted.
The word concerted in paragraph 2 mostly means _______.
A. partial
B. valuable
C. determined
D. complex