**Answer with explanation:**

**Graph drawn by Pauley ,for the change in temperature of hot tea:**

→Function Decreases Quickly first, and then decreases more slowly as time passes

If the equation of the function has been linear, there must have been constant rate of decrease of temperature.

Here,when we compose the function,that is , f(x)=y, where,

that is , y(temperature), decreases,when time increases.

Suppose this function is linear,represented as

→ y=k x, where k is the slope of line , a fixed real umber, it shows that,y and x are directly proportional to each other,that is when time increases ,temperature increases or vice versa.

**→But , here the situation is different,that is with increase in one variable(time),other variable (temperature), decreases . **

So,we can conclude that, the given function can’t be linear.

**Option D: It is nonlinear because linear functions increase or decrease at the same rate. is description about the situation Described.**