Identify the Surface $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } = 4$

Multiple Choice

Identify the surface $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } = 4$ .

A) ellipsoid but not a sphere
B) hyperboloid of one sheet
C) hyperboloid of two sheets
D) cylinder
E) sphere
F) elliptic but not circular paraboloid
G) cone
H) circular paraboloid (figure of revolution)