Which of the Following Concerning $\sigma$ And $\pi$ Bonds Is/are Correct?
1)A Sigma Bond May Be Formed from Correct

Multiple Choice

Which of the following concerning $\sigma$ and $\pi$ bonds is/are correct?
1) A sigma bond may be formed from the sideways overlap of two parallel p orbitals.
2) No more than two pi bonds are possible between adjacent carbon atoms.
3) The considerable energy required to rotate pi bonded atoms is the primary reason for geometrical isomerism in some pi bonded molecules.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 2 and 3