Assume the statements are true.

Statements: Some pigeons are hawks. All hawks are falcons.

Conclusions:

I. All pigeons being falcons is a possibility.

II. No pigeon is a falcon.

Explanation

1. 01

   The pigeons that are hawks are falcons, so 'Some pigeons are falcons' is definite. That makes 'No pigeon is a falcon' false: II does not follow.

2. 02

   Nothing stops the rest of the pigeons from being falcons as well. Draw all pigeons inside the falcon circle: the statements hold, so I follows.

3. 03

   Only I follows.