Answer
Refer answer below.
Work Step by Step
a. Domain : The set of all $(x,y)$ corresponding to $x^2+y^2 \lt 16$ .
b. Range: $z\geq \dfrac{1}{4}$
c. Level Curves: The level curves are the circles whose center is at (0,0) with radius $r \lt 4$
d. Boundary point lies at the circle $x^2+y^2=9$
e. Open only
f. Bounded