Which of the following is not positively influenced by physical activity?
a. cardiovascular disease
b. obesity
c. osteoporosis
d. allergies

D. Allergies. 

Cardiovascular disease is disease of the heart -- the more blood the heart pumps, the stronger it gets. Obesity is a disease of the flesh, and the more calories lost, the less flesh there is. Osteoporosis is a form of arthritis which afflicts the bones, and special exercises can help the user remain more limber.

Allergies are just allergies, man. You can't outrun nature. It's everywhere. 

That’s what i was going to say.

Answera tightly sealed house with an unvented water heater;