a)  A = {-3, -2, -1}
 b)  n(A) = 3
 c)  A is finite
Step-by-step explanation:
a) The elements of A are the integers between -4 and 0, not including those values. Those integers are -3, -2, -1, so those are the elements of set A.
 A = {-3, -2, -1}
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b) n(A) is the number of elements in set A. Obviously, there are 3:
 n(A) = 3
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c) Since n(A) is not "infinity", the set A is finite.