Answer:
The trans/trans stereoisomer.
Explanation:
So, we are going to have two stereoisomers or arrangements for this chemical compound, that is the Cis/trans, the trans/trans.
For a compound to be seen with UV, the main or primary condition is conjugation or how conjugated the chemical specie or compound is.
Thus, the more the conjugation, the more or the higher the wavelength or lands value.
=> The Trans/trans stereoisomer will have the highest lamda value or wavelength because the energy gap in its π - π* Transitioning deceases due to the STERIC interactions, and the more the decrease in the energy gap, the more or the higher the lamda value or wavelength.