The drawing shows a top view of a diffraction grating and the $m$ th$-$order principal maxima that are obtained with red and blue light. Red light has the longer wavelength. $($a$)$ Which principal maximum is associated with blue light, the one farther from or the one closer to the central maximum? $($b$)$ If the number of slits per centimeter in the grating were increased, would these two principal maxima move away from the central maximum, move toward the central maximum, or remain in the same place?

$($a$)$ farther $($b$)$ remain in the same place

$($a$)$ closer $($b$)$ away from

$($a$)$ farther $($b$)$ away from

$($a$)$ closer $($b$)$ toward