Which of the following hydrocarbon groups designated as I,II,III,Iv, and V has planar geometry?
`{:(Phenyl,Cyclohexyl,Cyclopentyl,Butyl,"Vinyl"),(I,II,III,IV,V):}`

Options

A. (1) IV
B. (2) I and V
C. (3) II and III
D. (4) II, III and IV

Answer

B

Explanation

For planner geometry, all the `C's` should be `sp^(2)` hybridized which is possible only in phenyl and vinyl :
, `H_(2)C = CH`
Others have `sp^(3)` hybridized `C's`.