Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks.

According to research conducted in the US, adult learners are the fastest growing segment of the population (23) ______ lifelong learning. The reason behind this trend is the fact that many professionals are beginning to realize that to remain competitive in the ever-changing world of business they need to stay current and (24) ________.

The markets and the economy are changing at a fast pace, and this means that anyone interested (25) ____ career development needs to be able to keep up. This is especially important since recent graduates will constantly (26) ____ your position as they will be more up-to-date with the changes in the industry.

And it's not as simple as learning a few computer skills here and there. For professionals across all industries to remain current they should closely follow trends and seek to provide depth in their industry knowledge. (27) ____, according to Scott Brinker, a marketing expert, marketers should have started learning to program since the turn of the decade.