Answer
Refer answer below.
Work Step by Step
a. Domain : The set of all $(x,y)$ corresponding to $x^2+y^2 \leq 9$ .
b. Range: $0 \leq z\leq 3$
c. The level Curves are the circles whose center is at (0,0) with radius $r \leq 3$
d. Boundary point lies at the circle $x^2+y^2=9$
e. Closed only
f. Bounded