Ken is moving to a new city and considering whether he should rent or buy an apartment. What factors should he consider in his decision?

A) His budget.

B) How long he plans to live in the city.

C) Financial stability of the housing market.

D) All of the above.

The factors that he should consider in his decision are D. all of the above.

He should definitely think about his budget, about whether he is able to afford buying an apartment in the city. He also needs to think about how long he plans to live there - if he is staying just for a short period of time, then it would be better to rent the apartment, instead of buying it. And finally, financial stability is another thing he needs to consider given that he may lose a lot of money if there is instability.