Registration fees usually range from _______ to _______. 

A. $50; $100 B. $15; $50 C. $45; $90 D. $25; $75

 B.

To find the answer to this question, you need to look at the given options and compare the ranges of registration fees.

Option A states that the range is from $50 to $100.
Option B states that the range is from $15 to $50.
Option C states that the range is from $45 to $90.
Option D states that the range is from $25 to $75.

By comparing these options, you can see that Option B, which states that the range is from $15 to $50, best fits the given question. So, the correct answer is B.