Determine a region whose area is equal to the given limit. do not evaluate the limit.

lim
n
→
[infinity]

n
∑
i
=
1

π
3
n
tan
(
i
π
3
n
)

a).
x
tan
x
on
[
0
,
π
3
]

b).
tan
x
on
[
0
,
3
π
]

c).
tan
x
on
[
−
π
3
,
π
3
]

d).
x
tan
x
on
[
−
π
3
,
π
3
]

e).
tan
x
on
[
0
,
π
3
]