Which of the Following Electronic Transitions Is Apparent in the Ultraviolet-Visible

Multiple Choice

Which of the following electronic transitions is apparent in the ultraviolet-visible spectrum of 1,3-butadiene?

A) "n $\rarr$ $\pi$ *"
B) " $\pi$ $\rarr$ $\pi$ *"
C) " $\sigma$$\rarr$ $\pi$ *"
D) " $\sigma$ $\rarr$ $\pi$ "