Consider the Utility Function Specified on Page 14-17 $u(x, r, c)$

Short Answer

Consider the utility function specified on page 14-17: $u(x, r, c)$ , where $x$ is the size of an individual's home, $r$ is their rank in home size relative to their neighbors, and $c$ is other goods. Which component of the utility function represents the notion of "other-regarding preferences?"
a. $x$
b. $r$
c. $c$
d. The curvature of $u($ . $) .$