Answer:
Option C.
Step-by-step explanation:
The given given sequence is
1, –3, 2, 5, –4, –6
We need to find the pairs of consecutive terms of the sequence and their product.
Pairs of consecutive terms | Product
1, -3 -3
-3, 2 -6
2, 5 10
5, -4 -20
-4, -6 24
Here the product of three pairs of consecutive terms is negative.
The number of variations in sign for the sequence is 3. Therefore, the correct option is C.
(0,0)
(1,3)
(2,4)
(3,3)
(4,0)
Vertex is (2,4)
ANSWER
{},{1}
EXPLANATION
The given set has one element. So it has

subsets.
These are,
{} and {1}.
That is, the null set and the set itself.
Remember that, the null set is a subset of every set and every set is a subset of itself.