Consider the function g(x)=x−1x,x=1. Which statement about the concavity of g is true?
a) g is concave up for x<1 and concave down for x>1; it has no points of inflection.
b) g is concave down for x<1 and concave up for x>1; it has a point of inflection at x=1.
c) g is concave down for x<1 and concave up for x>1; it has no points of inflection.
d) g is concave up for all x=1; it has no points of inflection.