Which of the following is a function from A ® B, where A = {1, 2, 3} and B = {2, 3, 4, 5}?

Here, we need to check the options and see which one has one element from A and the other from B in each pair, without having any pair with repetitions or elements from the same set. 

Option A has (1,1) contravenes the principle discussed above, as it has two elements from set A.

Option B is correct, as it has one element each from the two sets, and there is no repetition as such. 

Option C is incorrect, as the element '4' is repeated twice.

Option D is incorrect because of the same reason that was pointed out for Option A.