6) Given the function f(x) = In x, which of the following are true ?
P: f is increasing,
Q: f is equal to 0 when x = 0,
R: f has y-axis as an asymptote, and
S: f has a set of all real numbers as a range.
a) O P, Q and R only
b) O P and Q only
c) Q only
d) P, R and S only