Answer:
B. csc²(x)
Step-by-step explanation:
You can use the relations ...
sec(x) = 1/cos(x)
csc(x) = 1/sin(x)
cot(x) = cos(x)/sin(x)
to replace the functions in your expression. Then you have ...
sec²(x)·cot²(x) = (1/cos(x)·cos(x)/sin(x))² = (1/sin(x))² = csc²(x)
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Alternate solution
You can also use the relation
cot(x) = csc(x)/sec(x)
Then ...
(sec(x)·cot(x))² = (sec(x)·csc(x)/sec(x))² = csc²(x)
