Answer:
The 65 year old person is experiencing:
d. Decrease in his fluid intelligence
Step-by-step explanation:
Fluid intelligence is a typye of intelligence that refers to the hability to reason, analyze and solve problemes. This type of intelligence normally decreses within the years, this is why it affects elderly people. To solve a puzzle a person needs to use logic and pattern recognition, which are the functions of this type of inteligence.
Fluid intelligence requires physiologycal functioning, this is why old people do not have the same functioning as young people.