This question is worth 5 marks, answer all parts.

Carvone occurs naturally in a number of essential oils. One enantiomer of carvone is shown below.

[α] = +61°

a. Determine the number of stereogenic centres in the molecule. (1 mark) 

b. Determine the stereoconfiguration of the stereogenic centre(s) in the molecule following the Cahn Ingold Prelog rules. (1 mark)

c. Determine the number of stereoisomers that exist for this molecule. (1 mark)  

d. Predict the optical rotation for the enantiomer of the compound given. Explain your response. (2 marks)