Recently Pete has been having trouble with his memory; such as forgetting he put a kettle on to boil and leaving his store without locking up and turning off the lights. His friends laugh and say it's just part of turning 40. But Pete's mother died from early-onset Alzheimer's disease before age 50. What type of factors support Pete's heightened concern over his memory problems?
a. sociocultural
b. psychological
c. biological
d. life-cycle