Classes Rectangle and Point are defined as follow:

class Point:

def __init__(self,x,y):

self.x = x

self.y = y

class Rectangle:

def __init__(self,p1,p2):

self.p1 = p1

self.p2 = p2

Which option is showing the correct way of calculating the area of the rectangle in the Rectangle class?

a) def area():

return (self.p1.x-self.p2.x) * (self.p1.y-self.p2.y)

b) def area(self):

return (self.p1.x-self.p2.x) * (self.p1.y-self.p2.y)

c) def area(self,p1,p2):

return p1.x-p2.x*p1.y-p2.y

d) def area(p1,p2):

return area(p1*p2)

The correct way of calculating the area of the rectangle in the Rectangle class is option b):

```python
def area(self):
return (self.p1.x - self.p2.x) * (self.p1.y - self.p2.y)
```

Here's why:

In option a), the `area()` function is not defined as a method within the class, so it cannot access the instance variables `self.p1` and `self.p2`. To access instance variables within a class, you need to define the function as a method with the `self` parameter.

In option c), the `area()` method has additional parameters (`p1` and `p2`) that are not necessary because the points `p1` and `p2` are already stored as instance variables `self.p1` and `self.p2`. Therefore, there is no need to pass them as arguments to the method.

In option d), the `area()` function is defined outside the class, which means it won't be associated with any specific instance of the class. Additionally, the parentheses and multiplication operator are used incorrectly in the `return` statement.

Only option b) correctly defines the `area()` method within the Rectangle class with the `self` parameter. It accesses the x and y coordinates of the two points stored as instance variables `self.p1` and `self.p2` to calculate the area of the rectangle using the formula: `(p1.x - p2.x) * (p1.y - p2.y)`.