A concrete statement can be considered as a 'solid' statement. This means that the sentence must contain hard facts to manifest the credibility of the statement. As much as possible, you give specific examples and provide evidence for this. From the choices, the answer would be D.
The answer is the first sentence- <span>For the first time in decades, Baby Boomers have been outnumbered by another group--the Millennials</span>
The gut instinct follower is arguably the simplest decision maker and tends to choose the first option in haste.
When confronted with two possibilities and a handful of information on each, the instinct follower will generally form an immediate impression, and side with wherever that impression lands.
And mostly that is the correct decision but sometimes you just make the decision too quickly and waste it by choosing the very first option on the list.