Which $of$ the following $is$ not correct

$Oa.$ A lower Vin causes smaller step size

$Ob.$ Higher resolution causes smaller step size.

$Oc.$ Vref$+$ should $be$ chosen $tobe$ equal $or$ greater than the maximum volatge produced $by$ the $sensor.$

$Od.$ The channel selection $in$ ADCON$0$ determines the pin $to$ which the $sensor$ should $be$ connected