1. a decreases
b increases

2. a 17
b 8
c 104
d 4

3. a every 15 minutes
b every 30 minutes
c every hour
d every 4 minutes

1. B increases 
2. D 4
3. A. every 15 minutes

The exponent function can be described as an= a0(r)^n where
a0= the initial value
r= the ratio of growth of decay
n= the time

In this question, the initial value would be 120, the ratio would be 1.04 and the time would be 4t.
The ratio is 1,04 or can be said as 104%. The graph should be growing since the ratio is >1. So, the first answer is increases.
The ratio is 104% which means 4% more than the original value(100%). So the next answer would be 4%.
The time used in the graph is 4t and the unit used by t is hours. That means, the growing happens for every 1/4 hour. If you change it into minute, it would be: 1/4* 60 minutes/hour=  15 minutes