Answer:
OPTION A
OPTION B
OPTION C
Step-by-step explanation:
Irrational numbers are the subset of real numbers. Their decimal representation neither form a pattern nor terminate.
OPTION A: 
This is equal to
.
is non-terminating. So, it is an irrational number. Hence, the reciprocal of an irrational number would also be irrational. So, OPTION A is irrational.
OPTION B: 
This is equal to
. Using the same logic as Option A, we regard OPTION B to be irrational as well.
OPTION C: 
This is equal to
.
Both
and
are irrational. So, the product and the reciprocal of the product is irrational as well. So, OPTION C is an irrational number.
OPTION D: 
16 is a perfect square and is a rational number.
=
. This is equal to 0.25, a terminating decimal. So, OPTION D is a rational number.
OPTION E: 
4 is a perfect square as well.
, a terminating decimal. So, OPTION E is a rational number.