Not a function.
Work Step by Step
A function is a correspondence between a first set, called the domain, and a second set, called the range, such that EACH member of the domain corresponds to EXACTLY ONE member of the range. --- Keywords are emphasized. We see from the graphical definition of the correspondence that "Texas" from the domain has more than one corresponding value in the range (it has four). So, the "exactly one" clause has been violated. Not a function.