Answer
True
Work Step by Step
For each value of $n$, the values of $l$ can be $l = 0, 1, 2,...,(n-1)$
$2p$ means that $n=2$ and $l = 1$
Since $l \lt n$, then this subshell can exist.
$4f$ means that $n=4$ and $l = 3$
Since $l \lt n$, then this subshell can exist.
$3d$ means that $n=3$ and $l = 2$
Since $l \lt n$, then this subshell can exist.
$1p$ means that $n=1$ and $l = 1$
Since $l = n$, then this subshell can not exist.
One (and only one) of these subshells cannot exist.
