Final answer:
The maximum certification period for an asymptomatic patient 45 years or older with multiple CHD risk factors is between 30 and 40 years.
Step-by-step explanation:
The maximum certification period for an asymptomatic patient 45 years or older with multiple CHD risk factors is between 30 and 40 years according to the information provided. This means that the patient's certification period would be valid for a duration of 30 to 40 years.