This sentence is from the YDS exam, an official language proficiency test held in Turkey.
"The huge improvement in levels of readership in the 1960s largely coincided with the arrival of television,________.
A) but there was a dramatic increase in the number of people who spent their time watching TV.
B) thus people began to pay more attention to the best-selling books, especially detective novels.
C) because the production of cheaper pocket editions within reach of a wider range of the population fostered reading.
D) so the habit of book reading came to occupy proportionately less of people's leisure time.
E) while the readership of humour biography, and history was decreasing among the younger generation."
The correct answer was given as "D", which had made me think long and hard during the exam that it contradicts the word improvement. But after the exam, upon searching the sentence on the internet, I found the original. Now it does make sense to me, because the word literacy in the original was changed to readership. Here it is:
"Despite the buoyancy of the publishing industry and the vast improvement in levels of literacy, the level of readership in Spain is the lowest in Europe, both of books (around 50 percent of population) and of newspapers (in the mid 1990s, 105 copies sold per 1000 inhabitants, compared with the European average of 232). A number of factors contribute to this somewhat contradictory situation. One is the very common practice of reading newspapers freely supplied in the many bars that are a focus for much of the leisure activity outside the home. Another very obvious factor is that the huge improvement in levels of literacy in the 1960s largely coincided with the arrival of television and its rapid growth in popularity, so that the habit of book reading came to occupy proportionately less of people's leisure time."
The way it is written in the exam says the opposite of what the original says about readership. I think the sentence in the question should have been "the gradual decline in levels of readership..." so that it can be in agreement with what is given as the correct answer.