Hey!
It is important to understand that condiments are optional and are completely based on whether the customer wants them. For each of the 7 condiments, there are 2 possibilities-
- The customer would want it (present in the burger)
- The customer would not want it (absent)
Now coming to the solving part-
Since meat is a must, the customer would choose of the 3 types of meat available, which equals 3C1 =3
For and since each condiment has 2 possibilities, and there are 7 condiments, it comes out to be 2^7
and the answer would simply be the multiplication of both entities which is option E.
If you are thinking about option B) you are assuming that all the 7 condiments are present in the burger and there is just a change in their arrangement, which is not the case.
Hope this helps 