How many foreign keys are present in the relationship below?

PATIENT

Patient ID

Patient Name

PHYSICIAN

$\backslash$table$[[$Phyeiclan ID$,$Physician$\_$Namo$]]$

PATIENT TREATMENT

$\backslash$table$[[$Petient ID$,$Physician$\_$ID$,$TreatmentCCode,Date,Time,Rosists$]]$

TREATMENT

$\backslash$table$[[$Treatment$\_$Codo Description$]]$

$1$

$2$

$3$

$4$