How to find a condition which leads to deadlock in non-reentrant locks


A multithreaded program P executes with x number of threads and uses y number of locks for ensuring mutual exclusion while operating on shared memory locations. All locks in the program are non-reentrant, i.e., if a thread holds a lock l, then it cannot re-acquire lock l without releasing it. If a thread is unable to acquire a lock, it blocks until the lock becomes available. The minimum value of x and the minimum value of y together for which execution of P can result in a deadlock are:

A. x=1,y=2 B. x=2,y=1 C: x=2,y=2 D: x=1,y=1

Though, answer is option D but is there any possibility to have deadlock in other 3 options. If yes, then what it is because not able to visulaize other options. Kindly explain.