Help with a question

Hey can someone please help me with my hw, it counts as a quiz grade, here a a few im stuck on

the question is: the following are resitant:

a. lsrl
b. correlation coefficient
c. both lsrl and corel. coef
d. neither
e. it depends

Suppose we fit the least squares regression line to a set of data. What is true if a plot of the residuals shows a curved pattern?

the lsrl might not be a good model
or a straight line is not a good model for the data

Thanks a lot!!
more help

Linear regression usually employs the method of least squares. Which of the following is the quantity that is minimized by the least squares process?

A.Sum(yi-mean of yi)^2
b. Sum(xi-mean of xi)^2