The fact that you can see interference colors in an oil slick on a puddle gives evidence that the oll film a) has two reflecting surfaces b) is thin c) causes only 1 phase shift d) all of these e) two of these

Option A

Explanation:

The interference color in an oil slick on a puddle results from the interference  caused as a result of reflection of light waves from the top as well as from the bottom surface of the oil slick.

This causes a disparity in the path of light reflecting from the surfaces and hence the sunlight is a band of seven colors, i.e., VIBGYOR, the disparities in the path results in constructive interference of the light rays which enables us to see interference colors in an oil slick.

the answer to this question is 60 n