First read a passage and then answer the questions following that passage.
How can you improve your reading speed ? By taking off the brakes. You wouldn't think of driving a car with the brake on. Yet as a reader you probably have several brakes slowing you down. One very common brake is regressing-looking back every now and then at something already read. It is like stepping backwards every few metres as you walk-hardly the way to move ahead quickly. Regression may arise from a lack of confidence, vocabulary deficiency, or actually missing a word or phrase. It makes a long sentence seem even more complex as the eyes frequently regress. Eye movement photographs of 12,000 readers in America showed that university students regress an average of 15 times in reading only 100 words. The average student of class four was found to look back 20 times. In short, regression consumes one-sixth of your precious reading time. Release this brake and enjoy a spurt in reading speed.
In the context of the passage, what does 'regression' mean?

Options

A. Lack of desire to improve the reading speed
B. Looking back at what is already read
C. Lack of proper understanding of what one reads
D. Comparing the reading speed of school and university students