Answer:
Option B. +3 and +6
Explanation:
Zeff = z - s
where z is the atomic number, s is the number of shielding(non-valence) electrons
For Boron, electronic configuration is 1s²2s³.
z = 5, s = 2
Zeff = 5 - 2 = +3
For Oxygen, electronic configuration is 1s²2s²2p⁴
z = 8, s = 2
Zeff = 8 - 2 = +6