sp2 hybrid orbitals have 1. trigonal bipyramidal symmetry. 2. linear symmetry. 3. tetrahedral symmetry. 4. trigonal planar symmetry. 5. trigonal pyramidal symmetry.

4. trigonal planar symmetry.

Explanation:

The sp2 hybridization is formed with one s and two p atomic orbitals and form  trigonal planar symmetry. In sp2 hybridization, there are same valence shell in both the orbitals and it gives three equivalent sp2 hybridized orbitals that are separated by 120 degrees giving trigonal planar symmetry.

Hence, the correct answer is "4. trigonal planar symmetry.".

i would say b

explanation:

but i think i would need more information than that