title: synchronized method use as a mutex in java
body: <p>i coundn't understand an simple question,   </p>
  
  <p>what does a synchronized method use as a <code>mutex</code> in java-</p>
  
  <p>a) A globally declared mutex<br>
  b) A method's mutex<br>
  c) A owning object's(this's) mutex</p>
  
  <p>can anybody elaborate this?
  thanks in advance</p>