12) Which of the following properties are satisfied by the following function: f(x) =
[x²+1 for x<0
1
for x = 0
5x+1
for x>0
(I) f(x) is continuous
(II) f(x) is differentiable for all x
(III) f(x) is differentiable at x = -2
A) I and III only
B) I and II only
C) I, II, and III
D) III only
E) I only