The reason for change in bond angle in the different molecules having same hybridisation is given by:
Molecular orbital theory
Valence shell electron pair repulsion theory.
Valence bond theory
None
1. Electron pairs are always repelling each other and tries to remain far apart
2. Different electron pairs have different orders of repulsion: L.P-L.P > L.P-B.P > B.P-B.P
3. If lone pairs are not present then geometry is equal to shape else geometry is not equal to the shape.
This all is explained by V.S.E.P.R. theory.
Hence, option number (2) is correct.
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