This is a test of commonsense with single/multi-choices. Complete the next sentence:

How to make roasted aubergine soup
Cube aubergines and place in a large bowl of salted ice water.
Let sit for 20 minutes.
Preheat oven to 450 f (232 c).

OPT: (a). Lay cubed aubergines on an aluminium-foil lined baking sheet. Drizzle over olive oil, then dust with sea salt, cinnamon, and cumin. (b). Cut aubergine before roasting with a chopping knife. Slice them up from the abdomen; cut around the core and gut part. (c). Wash 1/4 cup unpeeled aubergine and run it under the warm water, splash with cold water, and rinse under cool water. Combine 1 small serving of roasted aubergine and 1/4 cup of mash together in an electric mixer. (d). Mash up a handful of aubergine until thick, and place them into a saucepan or bowl. Bring to boil over medium heat, then reduce heat to low and bring mixture to a simmer.
The answer is:
(a).