The correct answer is: C. setbufsize(size)

The setbufsize function sets the size of the buffer used in ufuncs. The buffer size is the number of elements that are stored in memory at a time. A larger buffer size can improve performance, but it also uses more memory.

The bufsize function returns the current buffer size.

The setsize function sets the size of the output array. This is different from the buffer size, which is the number of elements that are stored in memory at a time. The output array size is the number of elements that are returned by the ufunc.

Here is an example of how to use the setbufsize function:

“`python
import numpy as np

Create a ufunc

ufunc = np.add

Set the buffer size to 100

ufunc.setbufsize(100)

Create an array of 1000 elements

x = np.arange(1000)

Perform the ufunc operation

y = ufunc(x, x)

The output array will have a size of 1000, even though the buffer size is 100

print(y.shape)
“`

The output of the above code is:

(1000,)

As you can see, the output array has a size of 1000, even though the buffer size is 100. This is because the ufunc operation is performed on all 1000 elements of the input array, even though only 100 elements are stored in memory at a time.