Rules question on all-in raise

[Meatmaw]

If A raises and B goes all-in, (assuming there are others involved in the pot of course), is A allowed to reraise only if the amount B puts all-in constitutes the minimum raise amt?

i.e. A bets 100, B raises all in 200 or more, C calls, then A can reraise.

A bets 100, B raises all in < 200, C calls, then A may not reraise.

Are these two statements correct?

Thanks.