Is this a correct Singleton implementation?

Question

While preparing for a quiz, I have come accross a question about the Singleton design pattern. The code had these:
- public final static instance
- instance being initialized in a static block
- private constructor

The possible answers:
a) correct Singleton implementation
b) wrong Singleton implementation
c) an example of lazy initialization
d) an example of eager initialization
e) to be a Singleton, it requires a getInstance() method
f) it cannot be considered an implementation of a Design Pattern

Personally I would say that b) and e) are correct, but someone else told me that the correct answers are a) and d).
Can someone enlighten me? Thank you in advance!

Answer 1

this is a correct singleton implementation as you get an unique class instance (eager initialized in static block, do you doesn't need a getInstance() method)... as correct singleton implementation it can be considered as implementation of design pattern ;)