Explain some of the things that may change because of the increasing life expectancy and a growing older adult population.

One of the largest affects of an increasing aging population is that the age group that can work and support the elderly group becomes smaller, putting a strain on the economy as more of the fiscal policy of the country is spent on retirement, social security, and pension. If the retirement age isn't raised to compensate for there being less workers, there will be more people claiming the benefits of retirement. Pulling more money out in larger groups than what the working age-group can put in. This will lead to higher taxes because there will be less money left for the government to use on infrastructure, and less money for the next group of people to retire. 
More products (healthcare, retirement homes)  will also become geared towards the elderly since they will be largest group buying products, especially since their benefits of retirement will help to cushion them from the higher taxes unlike the working population.

“d” is the answer to the question

Ibelieve it's choice d.