Answer:
1st structure - Meso
2nd structure - Chiral
3rd structure - achiral
Explanation:
In the 1st structure there is nitrogen atom bonded with 4 different groups. It is Meso compound. In the second structure a carbon atom is attached with hydroxide molecule OH and has four different environment. It is Chiral compound. In the third structure no atom have different atom or group surrounding it. Therefore it is Achiral compound.
