Answer:
Most experts agree that only 30% of all new jobs are ever advertised. That means that the majority of opportunities never make it to the job boards. And typically, the more senior the position, the less likely the job is to be advertised.
Explanation:
B is the answer. If the problem is that people are not reading enough books, to conclude the text we would need a solution that can combat this problem. This would make the answer B.
I believe that the answer is A, to emphasize a point.