The correct option is C.
During the summer period, the weather is hotter compare to the winter period because the sun is closer to the earth. The walls of our houses absorb the more intense heat and radiate part of it into the house, this makes us to feel warmer.
Answer with Explanation:
We are given that




a.We have to find the expression for the minimum thickness the film can have ,t.
Condition for destructive interference


For minimum thickness m=0
Then, 
b.Substitute the values

Answer is B.
Because velocity is vector quantity, so magnitud and direction are needed to define it.
Since velocity means the speed(magnitude) of some object in a given direction, so it’s units are usually measured by meters/ seconds