Is there an interference maximum, a minimum, an intermediate state closer to a maximum, or an intermediate state closer to a minimum at point $P$ in the figure if the path length difference of the two rays is $($a$)2\mathrm{.}2,($b$)3\mathrm{.}5,($c$)1\mathrm{.}8,$ and $($d$)1\mathrm{.}0?$