When Developmentalists Considered Fluid and Crystallized Intelligence to Determine If

When developmentalists considered fluid and crystallized intelligence to determine if intelligence continues to grow,slow,or decline with age,what did they discovered?

A) Fluid intelligence does decline;however,crystallized intelligence holds steady and can improve.
B) Crystallized intelligence does decline;however,fluid intelligence holds steady and can improve.
C) Both fluid and crystallized intelligence decline with age.
D) Both fluid and crystallized intelligence improve with age.