Final answer:
According to the text provided, middle adulthood begins in the mid-30s and continues until the mid-60s, which means Manuel, who has just reached this stage, is at least 40 years old. The correct answer is option (b) 40.
Step-by-step explanation:
The question is asking at what age does middle adulthood begin according to the text
. Middle adulthood is a phase in life that is marked by various changes and begins after a certain age. According to the text provided, middle adulthood begins in the mid-30s and continues until the mid-60s. During this stage, individuals may experience signs of aging such as graying hair and wrinkles, as well as an increased risk of health problems such as heart disease, cancer, and diabetes.
It is also often the time for achieving career goals and experiencing the milestones of children growing up and leaving home.
Therefore, if Manuel has just reached middle adulthood, he is at least 40 years old. Hence, the correct option in the final answer to the question 'Manuel has just reached middle age as defined by the text. This means he is at least __________ years old.' would be (b) 40.