单选题：Which code below may cause deadlock?

Which code below may cause deadlock? @[C](2)

A.
```
in one thread:
syncronized(a) {
syncronized(a) {
}
}
in another thread:
syncronized(a) {
syncronized(a) {
}
}
```
B.
```
in one thread:
syncronized(a) {
syncronized(b) {
}
}
in another thread:
syncronized(a) {
syncronized(b) {
}
}
```
C.
```
in one thread:
syncronized(a) {
syncronized(b) {
}
}
in another thread:
syncronized(b) {
syncronized(a) {
}
}
```
D.
```
in one thread:
syncronized(a) {
syncronized(a) {
}
}
in another thread:
syncronized(b) {
syncronized(b) {
}
}
```



A.
```
in one thread:
syncronized(a) {
syncronized(a) {
}
}
in another thread:
syncronized(a) {
syncronized(a) {
}
}
```
B.
```
in one thread:
syncronized(a) {
syncronized(b) {
}
}
in another thread:
syncronized(a) {
syncronized(b) {
}
}
```
C.
```
in one thread:
syncronized(a) {
syncronized(b) {
}
}
in another thread:
syncronized(b) {
syncronized(a) {
}
}
```
D.
```
in one thread:
syncronized(a) {
syncronized(a) {
}
}
in another thread:
syncronized(b) {
syncronized(b) {
}
}
```


答案：C