The electron concentration in an n-type semiconductor is the same as hole concentration in a p-type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.
(1) No current will flow in p-type, current will only flow in n-type.
(2) current in n-type = current in p-type.
(3) current in p-type > current in n-type.
(4) current in n-type > current in p-type.