Best thing since sliced bread

Do you know the English phrase “the best thing since sliced bread“? Look at the conversation. Can you guess the meaning?

Naomi: I really like our new oven. It has so many functions, and I can make so many things in it!

Greg: I love it too. It’s the best thing since sliced bread!

Does it mean:

a) a good invention 

b) a good bread maker

c) a good kitchen appliance

d) a good bread slicer

The answer is below!↓

 

 

 

Answer: a) a good invention