On September $1,$ Powell Company received $$37,800$ for six months of rent, in advance. Powell credited Rent Revenue, which is an alternate way of recording the initial receipt of cash. If the appropriate adjusting entry is not made at the end of the year, what will be the effect on:

$($a$)$ Income statement accounts $($overstated$,$ understated, or no effect$)?$

$($b$)$ Net income $($overstated$,$ understated, or no effect$)?$

$($c$)$ Balance sheet accounts $($overstated$,$ understated, or no effect$)?$