\fSelect one or more: a. There are no obvious high-leverage points. b. Compared with other points, observation '4' I 53 is an Influential observation and it I could be a possible outlier. I c. Linearity assumption is violated. d. Independence assumption is violated. a. Constant variance assumption can be accepted since no severe non-constant variance problem appears. 1'. The residuals are slightlyr light tailed