Answer:
d. ser is used tl describe location
im native spanish speaker ser is like being or you are it depends on the sentence but in this case you cannot talk of a location with the word Ser
1. Is
2. Am
3.is
4. Is not
5. Is
6.am
7.is
8.is not
9.be
10.are
11.is
12.is
13.are
14.are
15.are
16.am
1. Vayan
2. Observen
Hope it helped!