Explanatin:
initially x and y are passed into this function using call by value printxy(1,1)
X is 1
y is 1
now what you are doing is assigning x=0
now x=0 y=1
PTR is pointing to x means it has x’s address
x’s value is now copied into y
x=0 and y=0
*ptr=1 means you are assigning value 1 to x
now x=1, y=0
Option C