Which one of these client factors will generally have the greatest influence on your decorating plan?
a. age
b. lifestyle
c. occupation
d. color preference

Well, all of these options have an influence on your decorating plan. Age does - because the plan will be different if you are making it for a child and a grown up. Also lifestyle matters - the way people live in their apartments. But also occupation does - if they have a good job, they will have money for all the decorations; if they don't, they won't. And color preference also matters - if you want to paint something blue and your clients don't like it, you will have to change that. So, all options are correct, I am not sure which one to pick.