Answer:
A. Plastic cover.
B. Plastic cover will be shinny and clear which will be acting like a plane mirror, instead use the clear plastic cover.
C. This does not affect much performance.
Explanation:
a. Instead of plane mirror we will use clear plastic cover
b. The clear plastic cover will be shinny and clear which will be acting like a plane mirror. So, in place of plane mirror we will place the clear plastic cover.
c. This modification will not affect much in the performance of kaleidoscope as the clear plastic paper will be exactly the same as the plane mirror.
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